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Roof to Table

Community Gardening - Fri, 08/08/2014 - 3:05pm


Stacey Kimmons, Windy city Harvest graduate, works on the rooftop garden at McCormick Place.

Stacey Kimmons, Windy city Harvest graduate, works on the rooftop garden at McCormick Place.

The Windy City Harvest and SAVOR partnership replaced roof garden at McCormick Place in 2013 with vegetables. Farm coordinator Darius Jones estimates the 2014 season will yield 18,000 pounds of produce. Read about this story and other successes in Roof to Table (PDF) from Landscape Architecture Magazine’s August issue. 




Rescuing Local Ravines

Plant Science and Conservation - Wed, 07/30/2014 - 11:00am

At first, the tree-shaded ravines near Lake Michigan look inviting, a place of filtered sunlight in the Chicago area’s North Shore. But the ravines—with homes built on the bluffs above them—are in trouble.

Overgrown with invasive plants that block the sun, the ravines are losing the native plants that help keep their soil from washing into Lake Michigan. Although some erosion is natural, the rate of erosion is accelerating, partly because of runoff from urban areas atop the ravines. The Chicago Botanic Garden and the Park District of Highland Park have stepped in to try to keep the ravines from crumbling any further.

“These are systems that have been beaten up for a long time,” said Rebecca Grill, natural areas manager for the Park District of Highland Park.

 A bike path along the bottom of Millard Park ravine, next to a small stream.

Millard Park is one of the many Lake County ravines that face challenges from erosion.

The Garden and the Park District have put together a scientific research and “ravine trauma” team to help reestablish native plant cover that will slow surface erosion. The team is developing a mix of native seeds that private landowners can sow to help restore vegetation to the slopes of ravine and bluff properties. The seeds will be sold commercially. In addition, the team will provide homeowners with a guide on how to care for the native plants.

“The Garden has a responsibility to partner with our neighboring communities to conserve and protect oases of biodiversity such as those found within the Lake Michigan ravines,” said Bob Kirschner, the Garden’s director of restoration ecology and Woman’s Board Curator of Aquatic Plant and Urban Lake Studies. “We’re pleased to be able to pair our ecologists’ knowledge with the Park District of Highland Park’s progressive approach of helping landowners help themselves.”

The project team includes Garden ecologist Jim Steffen. With 25 years of experience, Steffen has worked on other Lake County ravines, where the lake’s cooler, damper air is funneled to create a microclimate not found anywhere in Illinois. (The ravines also are home to some of the state’s rarest plants.) As part of the project, Steffen helped design a seed-trial experiment and develop potential seed mixes.

 Jim Steffen.

Garden ecologist Jim Steffen in the field

For the next three years, the seed mixes will be tested in plots within Highland Park’s Millard Park, one of the district’s four lakefront parks with ravines adjacent to Lake Michigan. (Check for more information.)

After that, the next step will be up to homeowners near the ravines. “We hope to build a better awareness about the potential they have to regenerate the diversity of native plants,” said Grill.

This post was adapted from an article by Helen Marshall that appeared in the summer 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and

Chicago Botanic Garden and University of Chicago partner in bid for Obama library

Community Gardening - Wed, 07/16/2014 - 1:42pm

All the possibilities for the Obama Library plus our Windy City Harvest Youth Farm are featured in the Chicago Tribune today! Read about it in Community groups pin hopes on Obama library (PDF).

 Windy City Harvest Youth Farm teen waters in the garden.

( Jose M. Osorio, Chicago Tribune / July 16, 2014 )
Oluwapelumi Ajayi, 15, waters vegetable beds at the Chicago Botanic Garden’s urban farm in Washington Park last month. Sophia Shaw, the botanic garden’s CEO, hopes the Obama presidential library will settle on the South Side and include a garden.

Click here to download a PDF of this article.
Copyright © 2014 Chicago Tribune Company, LLC

Praying Mantis “Children” in the Growing Garden

Youth Education - Wed, 07/02/2014 - 8:35am

One of our favorite insects at the Chicago Botanic Garden is the praying mantis. So we were very excited to obtain an egg case earlier this spring. We decided to keep it indoors so we could watch it hatch, and then release the newly hatched insects into the Garden.

 Preying mantid egg case on a twig.

About 100 praying mantises emerged from this ootheca and were released into the Grunsfeld Children’s Growing Garden.

A praying mantis egg case is called an ootheca (pronouned oh-uh-THEE-kuh). The plural is oothecae (oh-uh-THEE-see). The ootheca was produced by a female praying mantis last fall. She laid her eggs in this foam of protein that hardened around a stick and protected the eggs through the winter. The eggs usually hatch in mid-June to early July. The half-inch-long immature praying mantis nymphs resemble the adult, but they do not have wings. 

 Hundreds of baby mantids pour out of an egg case.

Colorless praying mantis nymphs emerge from the ootheca all at one time. During their first hour, they darken in color to blend in with their surroundings.

After our praying mantises hatched inside an insect cage, I discovered that a bed of false sunflower plants (Heliopsis helianthoides) in the Grunsfeld Children’s Growing Garden was infested with red aphids. I released the praying mantises, and the hungry babies immediately began to feed.

 Mantis nymphs on the head of a Rudbeckia flower covered with aphids.

At first, the praying mantis babies seemed a little bewildered by their new surroundings, but they quickly acclimated.

 Mantis nymph on a flower stem eyes aphids—a tasty meal.

This mantis held very still as it eyed its prey.

 A row of mantis nymphs on a leaf face a stem covered with red aphids.

These four little mantises lined up and stared at the aphids that would certainly become lunch soon.

It wasn’t exactly aphid carnage—much to the disappointment of our eighth grade Camp CBG helper, Joshua, who assisted me with the release—but the young predators did appear to enjoy their first meal.  

 Preying mantis on liatris bloom in August.

By the end of August, some of our little friends will be as big as this praying mantis (and just as hungry)!

It may surprise you to know that although it looked like a bad infestation, aphids are not really a big problem for the plants. When they are very abundant, it does not take long for natural predators like praying mantises and ladybugs to find them and move in for a feast. Predatory insects will take care of the problem if you are patient and let nature take its course. If aphids show up in your garden and they bother you, we recommend hosing them off with water rather than using an insecticide, because chances are pretty good that there are beneficial insects on your plants, too. Hosing with a strong jet of water will knock off all the bugs and kill most of the aphids, but it won’t be as devastating to the mantises or other beneficial insects as poison.

We have placed praying mantis oothecae in the Regenstein Fruit & Vegetable Garden and Elizabeth Hubert Malott Japanese Garden, as well as in the Children’s Growing Garden, to ensure that there will be a population of our favorite insect for you to find. Many of them will survive on aphids and other insects they capture and devour on our flowers, and they will grow up over the summer. The next time you visit, stop by and see if you can find them helping our plants remain healthy and less bothered by pests.

©2014 Chicago Botanic Garden and

The Ultimate Play Date: Kids + Nature

Youth Education - Mon, 06/23/2014 - 1:37pm

School’s out. The first official day of summer has come and gone. Time for life to move outdoors.

For some kids (OK, some caregivers, too), heading out to the backyard, the beach, the parks, and the forest preserves can feel daunting—what do you DO once you’re out there?

“Hands in earth, sand, mud: building, digging, sewing, baking—these are what humans DO.”

 A strip of astroturf is covered with an excercise course for ants made from twigs, stones, and other natural objects.

Build an ant playground out of sticks! Sue Dombro of the Forest Preserves of Cook County gave us tips for building one, adding this telling comment: “My daughter used to do this all the time, and now she’s a wildlife biologist.”

For fun, interesting, and education-based answers, we turned to a fun, interesting, and education-based crowd: the 190 teachers, home educators, day care providers, park district staff, museum employees, librarians, and just-plain-curious caregivers who came together at the Garden recently for our first Nature Play conference in May (sponsored by the Chicago Botanic Garden, Chicago Wilderness, and the Alliance for Early Childhood).

That morning, opening remarks were short, but sweet. A few thought-provoking highlights are quoted here. Then we did what any group of early childhood-oriented people would do: We all went outside to play.

At our outdoor “playground,” 19 organizations shared their fun, interesting, and education-based ideas for playing outside. You may recognize many from your own childhood.

1. Pick Up a Stick

How cool is this? In 2008, the stick was inducted into the National Toy Hall of Fame! It’s in great company: the jump rope, dominoes, the Frisbee, Tinkertoys and, yes, the Easy-Bake Oven are co-recipients of the honor. The possibilities of the stick are endless—it’s a musical instrument, a light saber, a wand, a fishing pole, a giant pencil for drawing in the dirt, a conductor’s baton, the first leg of a tepee, and anything else a child says it is.

2. Learn to Lash

If one stick is interesting, a pile of sticks has real 3-D potential. The art of lashing teaches kids to turn something small—two twigs lashed together—into something big: a ladder, a lean-to, a stool, a swing.

3. Find the Art in Nature

Twigs + stones + leaves + “tree cookies” + seeds = a nature “painting,” a sculpture, an imaginary animal, backyard trail markers, or utterly simple, charming drawings like the happy face made out of seeds shown with our headline.

“For children, the most powerful form of learning is with their hands.”

 A squirrel made from tree cookies, pine cones, acorns.

Imagination can run wild when kids are outside.

4. Nature as Paintbrush

Sure, you can use a standard brush to paint with, but feathers, pine needles, and arborvitae segments not only expand the creative possibilities but also feel wonderfully different in the hand.

5. Kid-Made Kites

Send the imagination soaring with a simple paper bag and a couple of kitchen skewers—in moments, it’s a kite! And then there’s the process of decorating it with ribbons and streamers…

6. Cricket Bug Box

Catch a cricket (or buy a dozen for $1 at the pet shop). Friendly and chirpy, crickets are many kids’ first experience with the insect world. Even little kids can collect the foliage, food scraps, and water-soaked cotton balls to accessorize a temporary shoe-box habitat.

“Nature is children’s real home.”

 A log and magnifying glass.

What’s under that log? Life.

7. Lift a Log

One of the simplest of all outdoor projects: lift up a log that’s been sitting on the ground and be amazed by the tiny wildlife that lives­ underneath it! Don’t forget to bring your magnifying glass.

8. Make a Magic Circle

Tuck a few wooden embroidery rings into a backpack. Placed on the ground in the woods, or the garden, or the sand, they become magical circles for kids to explore. What’s in yours?

9. D.I.Y. Dyeing

Rainy days need projects, too. Natural dyes made from vegetables (beets, onions), fruits (grape juice), or spices (turmeric, chili powder) transform undyed yarn or fabric into a personal style experience.

10. Paint Chip Color Hunt

One quick visit to the paint store can send kids off to hunt for hours, as they try to match nature’s colors to the humble paint chip card. (Handy to keep in the car for unexpected delays, too).

 A variety of paint chip cards with flowers that match the colors on the chips.

Simple but engrossing: match the colors in nature to the colors on a paint card.

Looking for fun things to do with the kids this summer? June is Leave No Child Inside month, so Chicago Wilderness/Leave No Child Inside has organized all sorts of ideas for you on Pinterest!

©2014 Chicago Botanic Garden and

Plant Breeding Program Takes Perennials to New Heights

Plant Science and Conservation - Sun, 06/08/2014 - 1:10pm

Interested in new perennials for your garden? How about ones that have proven to be exceptional—fragrant, colorful, drought tolerant, resistant to disease and pests, and hardy in the Midwest and similar climates? Just turn to our scientists, who have done the legwork for you through the Chicago Botanic Garden’s plant breeding and evaluation programs.

Breeding and selecting new perennials is a long, intense process that begins with cross-pollinating two plants, or moving pollen by hand from the flowers of one plant to the flowers of another plant with different traits. The two related plants—which ideally will produce exceptional offspring—are selected for breeding based on desirable attributes.

 Jim Ault poses in a bed of bright pink- and purple-blooming asters he developed at the Garden.

Jim Ault, Ph.D., with Symphyotricum (aster) hybrids developed at the Garden

 A closeup of the rich purple buds of Twilite false indigo.

Twilite false indigo (Baptisia × variicolor ‘Twilite’)

 Using tweezers, Jim Ault hand-pollinates a Baptisia.

Pollinating Baptisia

“In the best-case scenario, from the first cross to the final plant worthy of introduction, it takes about seven years, maybe eight to ten. I have to think long-term in generation time, from seed to first bloom to maturity,” said Jim Ault, Ph.D., plant introduction manager and Gaylord and Dorothy Donnelley Director of Ornamental Plant Research.

The most promising new plants are propagated by cuttings or tissue culture and then scrutinized by the Garden’s Plant Evaluation Program, managed by Richard Hawke. He compares the plants to cultivars and species already in the trade to ensure that the plants from the breeding program are unique and worthy of introduction. Hawke also recommends plants for use as parents in the breeding program.

 Richard Hawke crouches down, examining the progress of a cultivar planted at the Garden.

Richard Hawke at work

“The public can see about 80 percent of the breeding program plants as we are growing them in the ground in the evaluation gardens,” Dr. Ault said. Plants with the highest marks move to licensed commercial nurseries that also conduct field and container trials and then propagate the new plants for sale to home gardeners and the horticultural trade.

In recent years, popular offerings from the breeding program have included the first orange coneflower ever released, Art’s Pride coneflower (Echinacea ‘Art’s Pride’), and Forever Pink phlox (Phlox ‘Forever Pink’). “The interest in ‘Forever Pink’ has exploded,” Ault said. “It has three weeks of peak bloom in late May to early June and then it repeat-blooms on about 10 percent of the plant all summer and fall. It’s compact and, unlike other summer-blooming phlox, has had no powdery mildew whatsoever.”

You can expect to see more noteworthy perennials in coming years. Ault is hybridizing several types, including ground-cover phlox, asters, and other genera. “Something really wonderful should bloom this spring out of the hundreds of new seedlings that we’re growing,” said Ault.

Visit for a full list of the perennials released commercially through the Garden’s Plant Breeding Program.

 A closeup of the unusual bright orange color of Art's Pride coneflower.

Art’s Pride coneflower (Echinacea ‘Art’s Pride’)

 A bed of a dozen plantings of Forever Pink phlox in full bloom.

Forever Pink phlox (Phlox ‘Forever Pink’)

 Tidal Pool prostrate speedwell.

Tidal Pool prostrate speedwell (Veronica ‘Tidal Pool’)

Support for the plant evaluation program is provided by the Bernice E. Lavin Evaluation Garden Endowment, the Woman’s Board Endowment for Plant Evaluation Research and Publication, and the Sally Meads Hand Foundation.

This post was adapted from an article by Nina Koziol that appeared in the spring 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and

Plant Conservation Is Happening Right Over Your Head

Plant Science and Conservation - Thu, 05/29/2014 - 11:31am

What if the next plant conservation project wasn’t down the street, or in the neighboring county, or far away in the wilderness? What if it was right above your head, on your roof? In our increasingly urban world, making use of rooftop space might help conserve some of our precious biodiversity in and around cities.

 Ksiazek bending to examine blooming sedums on Chicago's City Hall green roof.

The green roof on Chicago’s City Hall supports an amazing diversity of hundreds of plant species.

Unfortunately, native prairie plants have lost most of their natural habitat. In fact, less than one-tenth of one percent of prairies remains in Illinois—pretty sad for a state whose motto is the “Prairie State.” As a Chicago native, I found this very alarming. I thought, “Is it possible to use spaces other than our local nature preserves to help prevent the extinction of some of these beautiful prairie plants?” With new legislation at the turn of the century that encouraged the construction of many green roofs in Chicago, it seemed like the perfect place to test a growing hypothesis I had: maybe some of the native prairie plants that were losing habitat elsewhere could thrive on green roofs.

This idea brought me to the graduate program in Plant Biology and Conservation, a joint degree program through Northwestern University and the Chicago Botanic Garden. Here, I am investigating the possibility that the engineered habitats of green roofs can be used to conserve native prairie plants and the pollinators that they support.

 Ksiazek examines plants in a prairie, taking data.

Which plant are you? In 2012, I surveyed natural prairies to determine which species live together.

Since I began the program as a master’s degree student in 2009, I’ve learned a lot about how native plants and pollinators can be supported on green roofs. For my master’s thesis, I wanted to see if native wildflowers were visited by pollinators and if they were receiving enough high-quality pollen to makes seeds and reproduce. Good news! The nine native wildflower species I tested produced just as many seeds on roofs as they normally do on the ground, and these seeds are able to germinate, or grow into new plants.

Once I knew that pollinator-dependent plants should be able to reproduce on green roofs, I set out to learn how to intentionally design green roofs to mimic prairies for my doctoral research. I started by visiting about 20 short-grass prairies in the Chicago region to see which species lived together in habitats that are similar to green roofs. These short-grass prairies all had very shallow soil that drained quickly and next to no shade; the same conditions you’d find on a green roof. 

 Ksiazek poses for a photo among prairie grasses.

Plant species from this dry sand prairie just south of Chicago might also be able to survive on green roofs in the city.

 Plant seedling.

A tiny bee balm (Monarda fistulosa) seedling grows on the green roof at the Plant Science Center at the Chicago Botanic Garden.

 Hand holding a seedling; paperwork is in the background, along with a seedling tray.

One of my experiments involves planting tiny native seedlings into special experimental green roof trays. They’re now on top of the Plant Science Center. Go take a look!

I’m now setting up experiments that test the ability of the short-grass prairie species to live together on green roofs. Some of these experiments involved using seeds as a cheap and fast way of getting native plants on the roof. Other experiments involved using small plant seedlings that may have a better chance of survival, although, as any gardener could tell you, are more expensive and labor intensive than planting seeds. I will continue to collect data on the survival and health of all these native plants at several locations, including the green roof on the Daniel F. and Ada L. Rice Plant Conservation Science Center at the Garden.

Ideally, I would continue to collect data on these experimental prairies to see how they develop over the next 50 years and learn how the plants were able to support native insects, such as pollinating bees and butterflies. But I didn’t want my Ph.D. to last 50 years so instead, I decided to collect the same type of data on green roofs that have already been around for a few decades. Because the technology is still relatively new in America, I had to go to Germany to collect this data, where the history of green roofs is much older. Last year, through a Fulbright and Germanistic Society of America Fellowship, I collected insects and data about the plant communities on several green roofs in and around Berlin and learned that green roofs can support very diverse plant and insect communities over time. We scientists are just starting to learn more about how green roofs are different from other urban gardens and parks, but it’s looking like they might be able to contribute to urban biodiversity conservation and support.

 Ksiazek collects insects from traps on a green roof in Berlin.

I collected almost 10,000 insects on green roofs in and around Berlin, Germany in 2013.

 Closeup of a pinned bee collected from a green roof in Berlin.

I found more than 50 different species of bees on the green roofs in Germany.

Now that I’m back in Chicago and have been awarded research grants from several institutions, I’m setting up a new experiment to learn about how pollinators move pollen from one green roof to another. I’ll be using a couple different prairie plants to measure “gene flow,” which basically describes how pollen moves between maternal and paternal plants. If I find that pollinators bring pollen from one roof to anther, this means that green roofs might be connected to the large urban habitat, rather than merely being isolated “islands in the sky,” as some people have suggested. If this is true, then green roofs could also help other plants in their surroundings—more pollinating green roof bees could mean more fruit yield for your nearby garden.  

 Aerial view of Chicago at Lake Michigan, with green rectangles superimposed over building which house green roofs.

The green boxes represent green roofs near Lake Michigan. How will pollinators like bees, butterflies, and moths move pollen between plants on these different roofs? This summer, I will be carrying out an experiment to find out.

There are still many questions to be answered in this new field of plant science research. I’m very excited to be learning so much through the graduate program at the Garden and to be collaborating with innovative researchers both in Chicago and abroad. If you’re interested in keeping up with my monthly progress, please visit my research blog at the Phipps Conservatory Botany in Action Fellows’ page

 A wasp drinks water from a flower after rain.

A friendly little wasp enjoys the native green roof plants on a rainy day in Paris.

And if you haven’t already done so, I hope you’ll get a chance to visit the green roof at the Plant Science Center and see how beautiful plant conservation happening right over your head can be! 

©2014 Chicago Botanic Garden and

Pioneering Woodland Restoration

Plant Science and Conservation - Sat, 05/10/2014 - 8:30am

Tranquil, peaceful, and serene are words often associated with the McDonald Woods, which wrap around the northeastern edge of the Chicago Botanic Garden. But to Jim Steffen, senior ecologist at the Garden, the oak woodland is a bustling center for natural processes and species, and may hold answers to unsolved scientific questions.

 Multi-flowered milkweed blooms.

Purple milkweed (Asclepias purpurascens) blooms in the McDonald Woods.

“Nothing out there exists by itself. It’s all a network,” said Steffen. Since he arrived at the Garden 25 years ago, he has used his powers of observation to document, study, and breathe life into the systems that sustain a healthy woodland.

In the late 1800s, most area native oaks were cleared for settlement, leaving behind a fragmented and altered landscape. Invasive plants, including buckthorn and nonnative critters, such as all of our present-day earthworms, moved in. The climate began to change. While many may have thrown up their hands and walked away from this complex puzzle, Steffen saw a treasure.

Taking Flight

At age 15, he began to explore the natural world in earnest and to grow the insight that guides him today. After taking a course in his community, he was federally licensed to band birds for research, a pursuit he followed for another 40 years. As he searched for hawks, owls, and other birds of prey, Steffen couldn’t help but notice the activity beneath his feet. Among the fallen leaves were scuttling rodents, insects, and blooming plants. He realized their presence was integral to the entire community of life in the woods.

 A clump of blooming sedge grass.

Carex bromoides is one of many sedge plants essential to the woodland ecosystem.

“I started getting more into how those things are related rather than just narrowly focusing on the birds or the plants,” he said.

Steffen developed a broad ecological background as he pursued his education and worked toward a career in conservation science. He was hired to manage 11 acres of woods alongside a nature trail at the Garden. Now, that management responsibility includes more than 100 acres.

Master Plan

Although he does not expect to recreate the exact natural community of the past, Steffen does aim to grow an oak woodland of today. “My goal is to increase the native species diversity and improve the ecological functioning that is going on in the Woods,” he said.

Early in his career, he successfully advocated to expand the managed area to include adjacent acres. His management activities and detailed inventory work has grown the number of species there from 223 to 405. Of those species, 345 are native to the region.

 The woods in winter, showing both cleared, walkable woods and unpassable buckthorn-infested area.

Invasive buckthorn plants are interspersed among the trees on the right, while they have been removed on the left.

The leaf canopy of the second-growth woodland was nearly 100 percent sealed when he arrived. It is now more open, allowing sunlight to punctuate the ground—encouraging the reproduction of oak species and promoting the flowering and seed-set of the native grasses, sedges, and wildflowers. The rewards of his work? Less carbon being released from the soil, improved water retention and nutrient cycling, and a place to bolster native species of plants and animals.

 Jim Steffen in full protective gear including helmet and goggles, up in a tree with a chainsaw.

Jim Steffen begins to remove an ash tree infested with the invasive emerald ash borer insect.

Each season brings new challenges. This winter, Steffen, his crew, and hired contractors carefully removed nearly 600 ash trees killed by emerald ash borers, cleared three acres of mature buckthorn, and conducted a six- to seven-acre controlled burn.

“It’s a difficult thing to do,” he said of oak woodland management. Steffen is grateful for each helping hand. “I’d say I’d be about ten years behind if it hadn’t been for my dedicated volunteers who help with the physically demanding work.”

Springing Into Action

This spring, Steffen and his team will begin to collect seed from more than 120 native plants they nurture in the Garden nursery and from dozens more in the woodland.

The process continues through November. It includes plants like the cardinal flower (Lobelia cardinalis), which was once common in Glencoe’s natural areas.

Native woodland plants are grown for seed in the Garden nursery.

Native woodland plants are grown for seed in the Garden nursery.

Berries are collected for seeding.

Berries are collected for seeding.

Steffen also collects seed from external natural areas, bringing new genetic diversity into the Woods to strengthen existing plant populations. (This is an increasingly challenging task, as 50 percent of his collection sites has been lost.) Collected seeds are scattered in prepared areas of McDonald Woods, either in the spring or fall, or sometimes in the middle of winter on top of the snow.


“Everything you see growing, walking, or flying in the woodland is just 10 percent of the picture. In any native ecosystem, probably 90 percent of the diversity is at and below the soil surface,” he said. An entire network of plants and other living organisms exist and interact there, helping to sustain what grows above them. Oak trees and most other native plants rely on entrenched fungi, for example, to deliver nutrients and water or protect them from herbivores and disease.

 Closeup of a tiny brown spider clinging to the back side of a leaf.

This tiny Pisaurina spider helps support the woodland ecosystem.

Microarthropods living in the leaf litter and soil, such as tiny springtails and mites, and larger organisms including spiders, also play important roles. Together with a volunteer, Steffen has dedicated 14 years of work to better understanding those interactions. They have found several species never found before in Illinois and some that even appear to be new to science. “We are still identifying some of the things we collected ten years ago,” Steffen said. And similar, rarely studied subcommunities exist higher up in the trees. “That’s another hint as to how complex the system is and how much we don’t know about it,” he added.

Some things are clear. A pioneer of oak woodland restoration, Steffen was among the first to notice that the natural layer of decomposing oak leaves and plant material was vanishing from the ground in the McDonald Woods and most other woodlands in the region. He attributes the effect to higher levels of nitrogen from the decomposing leaves of nonnative plants, and the presence of exotic, invasive earthworms. “Because so many organisms live in that layer and depend on it for survival, they are disappearing,” he cautioned.

But first, it is time to take in the rewards of winter. May is peak season for migrating birds in the Woods, including warblers and flycatchers. Sedges will bloom, along with spring ephemerals such as trillium.

 A spare woods has dappled sunlight throughout.

The lush woodland landscape is healthy today.

Activity is everywhere, and it is a welcome sign of progress for Steffen. “It’s much healthier now than it was when I started,” he said. “All this diversity is able to function more easily now.”

The McDonald Woods are also an educational resource. Steffen will lead a rare off-trail hike there this year, and teach classes in bird watching and sedges through the Garden’s Adult Education programs.

Learn more about Jim Steffen and watch a video about his work.

©2014 Chicago Botanic Garden and

Bottle Cap Bouquets

Youth Education - Sun, 05/04/2014 - 8:50am

Miniature flower arrangements offer a charming and whimsical gift for mom, grandma, or anyone special. A nice feature of these tiny bouquets is that you can show off the beauty of small flowers that always sing backup to showier blossoms in large arrangements. Also, you can use aromatic herbs with small leaves as filler greens to add a pleasant scent.

 The supplies for creating bottlecap bouquets.

The supplies for creating bottle cap bouquets.

 a tiny bouquet of mini carnation, baby's breath, and a sprig of sage.

This little arrangement of mini-carnations, baby’s breath, and a sprig of sage has pink burlap ribbon wrapped around the bottle cap to mimic a fancy basket of flowers.

What you need:

  • A cap from a plastic bottle, such as a milk container or soda bottle
  • Floral foam (the wet kind)
  • A bunch of small flowers—I used mini-carnations, waxflowers (Chamelaucium uncinatum), and baby’s breath (Gypsophila paniculata)
  • Fresh herbs (thyme, rosemary, and lavender work well because they have stiff stems)
  • Optional: ribbon for added decoration

The directions are pretty simple.

Cut the floral foam to fit the inside of the bottle cap. Start a little larger than you need, and then trim it to fit. Push it into the cap. If your cap is narrow, like a milk bottle cap, you may want the foam to be above the level of the cap so there is enough room to hold the flowers. Otherwise, trim the top so the foam does not stick up. Add water to soak the foam.

 hands tracing around a bottlecap and block of foam with a pencil.

Trace the cap on a piece of foam and then carve the foam with a butter knife to fit inside the cap.

 hands poking flowers into floral foam.

Begin sticking the flowers into the foam. Here, we started with a waxflower in the center and added smaller flowers and herbs around it.

Cut the flower and herb stems about 3 inches. You can trim them shorter depending on the desired height in the arrangement. Stick them into the foam. You might want to start with one of your larger flowers in the center and then add smaller flowers and herbs around it.

 a tiny bouquet of waxflower, baby's breath, and rosemary.

Waxflower, baby’s breath, and rosemary complete this delicate arrangement.

 a tiny bouquet of baby's breath and thyme.

Not into pink? This yellow cap with baby’s breath and thyme is fragrant and cheerful.

When you are satisfied with your floral creation, you can either leave it as is—especially if the color of the bottle cap looks nice with the flowers—or you can tie a ribbon around the bottle cap. The best way to keep it in place is by using a few drops from a hot-glue gun. 

 a tiny garden created in an old contact lens case.

Surprise! An old contact lens case becomes a miniature garden of waxflower and thyme that smells as amazing as it looks.


When using a shallow bottle cap, limit the number of larger flowers like mini-carnations or mini-daisies to three or fewer. Floral foam has limits. Adding too many flowers will cause the foam to fall apart and the flowers to flop over. If the first attempt suffers from floppy flowers, start over with a new piece of foam and add fewer flowers. 

If you really want more than three large flowers, use a taller cup, such as a medicine cup from a bottle of cough syrup, as the vase. Even then, take care not to overload the foam. This is a small bouquet, after all!

 the final bottlcap bouquet arrangements in a group.

Precious and colorful, these-mini bouquets will stay fresh and bring cheer for a few days.

Floral foam is irresistible. Your kids, even teenagers, will want to play with it. Parcel it out in small pieces so they don’t play around with the whole block before you can use it. 

You can use the same procedure to make a mini-dried flower arrangement; just don’t wet the foam. Any way you make them, these little bouquets are sure to bring big smiles from someone you love. 

©2014 Chicago Botanic Garden and

Enriching the Lives of Future Plant Scientists

Youth Education - Thu, 04/17/2014 - 1:07pm

On any given day, the Chicago Botanic Garden’s science laboratories are bustling with activity. Some of the researchers are extracting DNA from leaves, analyzing soil samples, discussing how to restore degraded dunes—and talking about where they’re going to college. The young researchers are interns in the Garden’s College First program, studying field ecology and conservation science, and working side by side with scientists, horticulturists, and educators.

 Orange-shirted middle schoolers examine palm trees and take data in the greenhouse.

Science First participants gather data in the Greenhouse.

 Two high school girls wearing blue "College First" tshirts and latex gloves examine samples in the lab.

Two College First participants work on analyzing samples in the Garden’s plant science labs.

The Science Career Continuum consists of five programs:

  • Science First, a four-week enrichment program for students in grades 8 through 10.
  • College First, an eight-week summer internship for high school juniors and seniors with monthly meetings during the school year.
  • Research Experiences for Undergraduates (REU), a ten-week summer research-based science internship supervised by a Garden scientist and funded through a National Science Foundation grant. In 2014, three College First graduates will participate.
  • Conservation and Land Management (CLM) internship, offered through the Department of the Interior’s Bureau of Land Management and held in 13 western states.
  • Graduate programs in plant biology and conservation, offered jointly with Northwestern University for master’s degree and doctoral students.

The program is part of the Science Career Continuum, which is aimed at training the next generation of dedicated land stewards and conservation scientists. The Continuum engages Chicago Public Schools students from diverse backgrounds in meaningful scientific research and mentoring programs from middle school through college and beyond. “Each level of the Continuum challenges students to improve their science skills, building on what was learned at the previous level and preparing them for the next,” said Kathy Johnson, director of teacher and student programs.

College First is a paid eight-week summer internship for up to 20 qualified students. Isobel Araujo, a senior at Whitney Young High School in Chicago, attended the College First program in 2011 and 2012. As part of the program, she did research on orchids and learned how to estimate budgets to fix hypothetical ecological problems. “It was definitely challenging, but it was awesome,” said Araujo, who plans to major in environmental studies.

During the school year, College First students also attend monthly meetings that help them select colleges, complete applications, and find financial aid to continue their education. More than 94 percent of College First graduates attend two- or four-year colleges, and many are the first in their family to attend college. Three students, including Robert Harris III, received full scholarships to universities beginning in fall 2013.

Harris is a freshman at Carleton College in Northfield, Minnesota. As a junior and senior at Lane Tech High School in Chicago, he made a three-hour daily round-trip commute to the Garden for the College First program. During his internship, he learned to extract plant DNA and study genetic markers in the Artocarpus genus, which includes breadfruit and jackfruit. Harris said the program was a great experience. “You get out of the city and experience nature close up,” he said. “The Garden itself is one big laboratory, and it was a lot more hands-on than in high school.”

 An intern carries a quiver full of marking flags, and takes notes on her clipboard.

Science First and College First programs lead into other graduate and postgraduate programs. Visit to find information on these programs.

 A group of about 50 people pose at the end of the Serpentine Bridge.

Conservation and Land Management (CLM) postgraduate interns for 2013 pose for a group photo at the Garden. Visit to find out more about this program.

Because of funding restrictions, enrollment for the Continuum programs are limited to students from Chicago Public Schools. For more information, visit or call (847) 835-6871.

This post was adapted from an article by Nina Koziol that appeared in the spring 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and

In Bloom in the Garden, April 01, 2014

What's in Bloom - Tue, 04/01/2014 - 9:40pm
The dramatic banana plant (Musa x paradisiaca), a hybrid of Musa acuminata x Musa balbisiana, is a member of the Musaceae family often incorrectly referred to as a tree. It is actually a large perennial herb, with succulent, very juicy stems that arise from a fleshy rhizome or corm and reach a height of 20 to 25 feet. The huge, smooth, paddle-shaped leaves can grow as large as 8 feet. They number from 4 to 15 and are arranged spirally around the stems. They unfurl upward and outward at the rate of one per week in warm conditions. The flowers first appear as large, long, oval, tapering, purple-clad buds, which are actually waxy, hood-like bracts that cover the flowers inside. As they open, slim, nectar-rich, tubular, toothed white flowers are clustered in whorled double rows along the floral stalk. Hardy in USDA Zones 9-11, the banana plant is an ornamental, tropical-looking houseplant that in the Chicago area should be grown indoors in organically rich, moist, well-drained soil in full sun. Edible bananas originated in the Indo-Malaysian region, reaching to northern Australia. They were known as early as the third century B.C.E. Commonly called edible banana or French plantain, the genus is named for Antonia Musa, a first-century B.C.E. Roman physician.
The canary tree mallow is a tropical tree that produces a canary-yellow terminal (at the tip of the branch) and axillary (formed in the leaf axils) corymbose inflorescence (flat-topped clusters of flowers) in winter in the Chicago area. With a native range from Mexico south to Colombia and Venezuela, the flowers can vary from pale yellow through gold, sometimes with a red blotch near the center of the flowers. Grow canary tree mallows like abutilons — in full sun, in well-drained soil, and cut back the 12-foot-tall plants to a more manageable size during the dormant nonflowering season, from late winter to early spring.
Genista canariensis, commonly known as Canary Island broom, is a shrubby member of the pea family (Fabaceae) endemic to the Canary Islands, off the northwest coast of Africa. For years it was taxonomically placed in the genus Cytisus. For two to three weeks in early spring, it is covered with masses of fragrant gold flowers. The delicate little leaves have three leaflets, resembling clover, to which it is related. It requires cool nights, under 60 degrees Fahrenheit to flower, but cannot withstand frosts. Despite its limited natural distribution, Genista canariensis has become widespread in natural communities in southeastern Europe, California, and Washington.
A striking member of the Bromelioideae family, the urn plant (Aechmea zebrina ‘Surprise’) is an exotic, stately plant with beautiful, spiky, bright orange flowers held upright above rosettes of wide, thick, strappy gray-green leaves with dark stripes on the underside and backward-curving spines along the edges. The stunning flowers can last for months, making this one of the most popular bromeliads for the home. It should be planted in fast-draining potting soil with its central cup filled with fresh water, where it will thrive in indirect to moderate light in temperatures above 55 degrees Fahrenheit. Native to Mexico through South America, bromeliads are epiphytic (growing on trees) plants whose name comes from the Greek aichme (spear). They are technically air plants that use their roots for support.

Shoreline Showtime

Plant Science and Conservation - Sat, 03/29/2014 - 9:22am

The dress rehearsal is complete, spring is preparing to turn on the lights, and within a few weeks the curtains will go up on the Chicago Botanic Garden’s newest shoreline restoration—the North Lake.

According to Bob Kirschner, Woman’s Board Curator of Aquatic Plant and Urban Lake Studies, the project that began in 2010 will come to full fruition this year.

“One of the most important details is the maintenance and management after it is installed,” he said.

Since the restored North Lake was dedicated in September 2012, its 120,000 native plantings have been busy growing their roots as far as 6 feet deep into the soil, trying to establish themselves in their new home. The process has been all the more tenuous due to the barrage of extreme weather during that time, from droughts to floods to the deep freeze.

 Bob Kirschner poses on the restored lakefront.

Bob Kirschner was trained as a limnologist, or freshwater scientist.

“The first few years after a large project is installed, we’re out there babying the native plants as much as we can because these plants are serving an engineering function,” said Kirschner, who explained that plant roots play an integral role in the long-term stability of the shoreline and are essential to the success of the entire restoration.

Wading In

The Garden’s lakes were rough around the edges when Kirschner arrived 15 years ago. Wrapped in 60 acres of water, the land was eroding where it met the lakes.

Although the Garden could have surrounded the shores with commonly used barriers such as boulders or sheet piling, Kirschner advocated another route.

“We’re using much more naturalized approaches,” he explained. “They are taking the place of conventional, structural approaches.”

Why? In the long run, the shoreline becomes relatively self-sustaining. In addition to preventing erosion, it offers habitat for native wildlife such as waterfowl and turtles, and filters water to help keep it clean. When the plants flower, a shiny bow of blooms wraps all of those benefits up in a neat package.

 View across the lake of the Cove; swamp loosestrife is in bloom.

The North Lake shoreline restoration surrounds the Kleinman Family Cove.

Bright Ideas

For many Garden visitors, a stop at the shoreline is inspirational. “We’re trying to help them visualize that native landscapes can be created within an urban context to be both beautiful and ecologically functional at the same time,” said Kirschner, who counts on the attractive appearance of the plantings to open conversations about restoration, and how individuals can generate similar results. “When thoughtfully designed, you can have both the ecology and the aesthetics,” he added. 

It was this concept of incorporating the art and science of restoration in a public setting that brought him to the Garden in the first place, after more than 20 years as an aquatic ecologist with Chicago’s regional planning commission.

Kirschner, who is also the Garden’s director of restoration ecology, has managed six Garden shoreline restorations incorporating a half-million native plants.

 Marsh marigol (Caltha palustris) in bloom along the shoreline.

Marsh marigold is a harbinger of spring.

He and his team know where all of the plants are, and they track them over time to identify those best suited for urban shoreline conditions. His favorites include sweet flag (Acorus americanus), common lake sedge (Carex lacustris), swamp loosestrife (Decodon verticillatus), and blue flag iris (Iris virginica). Perhaps the most exciting of them all is marsh marigold (Caltha palustris), the first shoreline plant to bloom each spring.

Natural areas comprise 225 of the Garden’s 385 acres.

According to Kirschner, the Garden’s hybrid approach to shoreline restoration, which incorporates ecological function and aesthetic plantings, is unique. “Part of our mission as environmental scientists is finding a way to make our work relevant and valued by as much of the public as we can reach,” he said. “It’s emotional for me because I believe so strongly in it, and that this is a path to increase ecologically sensitive landscape values within American culture.”

Changing Seasons

 Drifts of native plants along the restored shoreline.

Drifts of native plants are a hallmark of the Garden’s restored shorelines.

The North Lake was his last major shoreline restoration for the time being. He is looking forward to taking a breath of fresh air and enjoying the show this spring. “It should be really interesting to watch how this year progresses,” he said. Because the long winter may mean a compressed spring, he said the blooms could be that much more intense once they begin in about May. “Every day when we come to the Garden, the plants will be noticeably bigger than they were the day before,” he anticipated.

When Kirschner finds a moment for reflection, he wanders over to the Waterfall Garden, where he enjoys serenity in the sound of the rushing waters, and walking the two staircases that invite discovery along the way.

©2014 Chicago Botanic Garden and

Making a Splash with Orchids

Plant Science and Conservation - Wed, 03/05/2014 - 10:05am

Anne Nies hopped off the corporate ladder and landed in a wetland. There, she was charmed by the enchanting yet elusive white lady’s-slipper orchid (Cypripedium candidum). Or maybe it was the mountain of data that pulled her in.

 Anne crouched in the field on a sunny day, in sun hat and gardening gloves, scribbling notes.

Anne Nies at work in the field.

After years of working in management, Nies enrolled in a master’s degree program with the Northwestern University-Chicago Botanic Garden Graduate Program in Plant Biology and Conservation. She was curious to see how she could apply her mastery of numbers and modeling from an earlier degree in mathematics to conservation challenges.

Now 1½ years later, as she prepares to graduate in June, she is completing a study of the state-threatened orchid that has a spotty record of success in Illinois.

Working with more than ten years of data collected by Plants of Concern volunteers, she has sorted through some perplexing trends with the delicate white plants. The orchids showed varied success levels in separate locations that are all classified as high-quality prairie. If the locations were equally strong, then what was causing certain populations to thrive and others to falter?

It was a question Nies had to answer, because, as she explained, when one of these plants perishes, it is almost impossible to restore or replace.

 The orchids in the field; surrounded by taller grasses and plants.

White lady’s-slipper orchid can be camouflaged by surrounding foliage.

“What I’m looking at is how the population has access to nutrients in its habitat and how that drives population behavior,” she said. “What are the nutrients that are available to the population, and how does that affect the plants’ behavior, and in particular, how does that affect flowering?”

After a preliminary review of the data, armed her with questions and theories, Nies traveled into the field in the spring and again in the fall for a first-hand analysis.

The initial challenge was to actually find the plant. When it isn’t flowering, white lady’s-slipper blends in easily with surrounding foliage. So she learned where to look and found herself returning again and again to wet and sandy locations, such as wetlands, within the prairie ecosystem.

“Orchids in general tend to be really specific in their habitat,” she said. “I realized there was probably something really different between the prairie as a whole where the orchids live and the specific spot where they are growing.” 

Nies brought back samples of plant tissue, soil, and even root tissue where fungus lives to the Garden’s Soil Laboratory in the Daniel F. and Ada L. Rice Plant Conservation Science Center for exploration.

She hoped to find that a high level of fungus, which lives in the roots of many orchid species, was leading to the healthier populations. But that wasn’t what she found. 

 Microscopic image of beneficial orchid fungi.

Helpful fungi live in the roots of orchids and can be identified through a microscope.

Lab results showed that in locations with nutrient-rich soil, the plants had high levels of the beneficial fungi. They also had low levels of photosynthesis—the internal process that creates food from sunlight for a plant. They were not doing very well.

In locations where the plants had higher levels of photosynthesis, Nies found that they had soil low in nutrients.

“What I’m hoping is that knowing the nutrient levels and the high sand composition can help maybe inform land managers and also with the propagation of this orchid,” she said.

Nies plans to incorporate this information with her pending conclusions into her final thesis for her master’s program, before going on to pursue a doctoral degree in the near future.

Much like math, according to Nies, everything is connected in botany, which is what makes it appealing to study. “One of the reasons I’m so interested in orchids is because they are so deeply connected to their habitat,” she explained.

 Anne Nies.

Anne Nies explores the Tropical Greenhouse.

Even though she has transitioned to botany, Nies will surely stay connected to her background in pure math, bringing a new perspective and skills to mounting scientific challenges. “It’s amazing to me how much we still don’t know, and how much is out there that still needs to be learned,” she said.

When she has time to wander, Nies heads to the Garden’s Tropical Greenhouse, where there is always another plant calling her name.

©2014 Chicago Botanic Garden and

How to Make Mushroom Spore Prints

Youth Education - Mon, 02/24/2014 - 9:23am

Mushrooms reproduce by making billions of spores that spread and grow into new organisms. You can take advantage of this phenomenon to make a beautiful print on paper.  

How to Make Spore Prints

All you need are some fresh, open mushrooms, paper, and a bowl. You can use mushrooms found growing outside or buy them from the market. When selecting mushrooms for spore prints, look for these things:

  • The cap should be fully open with the gills exposed
  • The gills should look good, not wet and mushy
  • The mushroom should feel slightly moist but not wet; dry mushrooms will not work
  • There shoud not be mold spots on the mushroom
  • They should look like mushrooms you want to eat
 Underside of a portabella mushroom.

This portabello mushroom is good for making spore prints.

 Shiitake mushroom.

This shiitake mushroom may be a little old—notice the brown spots on the cap’s edges—but should work.

First, you should remove the stems. I use scissors so I don’t pull up or damage any of the gills.

Place the mushrooms with the gill side down on a piece of paper. Mushrooms with dark gills, like portabellos, have dark spores that show up well on white paper. Shiitake mushrooms have white gills and spores that will show up better on black paper. Some mushrooms make both dark and light spore prints.

 Mushrooms, gills down, sitting on black construction paper.

These four shiitake mushrooms were placed on black paper. They will be covered with a bowl and then left overnight.

Place the paper on a tray or other surface that can handle something wet sitting on it because moisture from the mushrooms will soak into the paper and anything underneath it. Cover the mushrooms with a bowl to prevent them from drying out. Really ripe mushrooms will make a print in an hour, but I suggest that you leave them overnight to be sure you get results.

In the morning, carefully lift your bowl and the individual mushrooms and see what you get. If the paper absorbed a lot of moisture from the mushrooms, it may need to dry before you see the print very well—especially prints made on black paper. Portabello prints often show well-defined gills. Shiitake gills are not as straight and rigid as portabello gills, so you’ll get less gill definition in the print and a more wavy, swirling print. If your mushrooms are too wet, or are starting to rot, you’ll get more of a watercolor effect instead of a sharp print.

 Mushroom spore print.

If all goes well, billions of spores will fall from the mushroom and produce a pattern that resembles the gills on the underside of the cap, like this portabello mushroom print.

 Mushroom spore print.

Four shiitake mushrooms leave ghostly impressions on black paper. The swirled edges were made by the uneven surfaces of the mushroom caps.

 Mushroom spore print.

The fine lines on this print look like they might have been drawn by an extremely sharp pencil, but the spores that compose the image are much smaller than the tip of a pencil.

A Little More about Mushroom Spores

Garden scientist Louise Egerton-Warburton recently told me, “Plants are cool, but fungus rules.” As a mycologist, fungus is her passion. Now, we aren’t really interested in competition or ranking organisms by levels of interest or importance because every living thing needs the others to survive. But the fact remains that we tend to forget about smaller things, especially those that tend to be hidden from view, so let’s take some time to meditate on mushrooms.

 Stinkhorn fungus.

This stinkhorn fungus, Mutinus elegans, is growing out of the ground, but that is where its resemblance to green plants ends. It’s named for its obnoxious odor, which attracts flies that help distribute its spores.

Scientists used to think of mushrooms and other fungi as special kinds of plants. The problem is that, unlike plants, fungi do not get energy from photosynthesis. They are composed of different kinds of cells, they complete a different life cycle, and let’s face it: they don’t really even look like plants. So fungi are now grouped in their own kingdom of organisms, and nobody expects them to be anything like plants.

There are many different kinds of fungus, so for simplicity, let’s just think about the familiar mushroom with its stem and cap. This structure is actually the reproductive part of the organism, in the same way fruit is a reproductive structure in plants. (But we are not comparing plants and fungus!) Beneath the soil where you find mushrooms growing, there is a network of branching thread-like structures, called “hyphae,” which grow through the dead plant and animal matter in the soil and absorb nutrients. This is the main “body” of the fungus. As the fungus digests organic matter, it decomposes, making it useful for plants.

 Laetiporus sulphureus fungus, or "Chicken of the Woods".

This “chicken of the woods” fungus, Laetiporus sulphureus, doesn’t look like a mushroom, but it also produces spores.

 Mushrooms decomposing bark on the forest floor.

The fungus that produces these mushrooms is decomposing leaves and sticks that have fallen to the forest floor.

Back above ground, when conditions are favorable, a mushroom grows up from the hyphae. It matures and releases spores, which are like seeds. (It’s really hard to get away from comparing fungus with plants!) Spores are structurally different from seeds, even though they function to spread the organism in a similar way. Spores are microscopic and are so small that mycologists measure them in microns. A micron is one millionth of a meter.

 A ruler measures the tip of a pencil lead.

How many spores could fit on the tip of a sharp pencil? A lot! No wonder the spore print is so fine and delicate!

Look at a metric ruler. See the smallest lines that mark millimeters? Imagine dividing a millimeter into one thousand equal parts. Fungus spores measure 3 to 12 microns. It hurts my eyes trying to imagine a spore sitting on my ruler. We can only see them when there is a mass of them on a spore print. Mycologists use a micron ruler built into their microscopes to measure the individual spores.

Tiny but essential: Fungus rules.

©2014 Chicago Botanic Garden and

Photosynthesis Made my Rock Candy

Youth Education - Fri, 02/07/2014 - 8:30am

While you are inside wondering if winter will bring another chilling polar vortex, or six feet of snow, or 40 degrees Fahrenheit and rain, join me in contemplating the sweetness of plants.

 Burgundy leaves of the Bull's Blood sugar beet.

The common sugar beet, Beta vulgaris (this one is cultivar ‘Bull’s Blood’), is the source of our refined white sugar—not sugar cane!

All sugar comes from plants. All of it. Plants are the only thing on earth that can make sugar, and plants are made of sugars. Even plant cell walls are composed of a substance called cellulose, which is a compound sugar. Sugars from plants are the basis of our food chain.

Our favorite dietary sugar, sucrose, comes from the juices of sugar cane or sugar beets, which are boiled until the water evaporates, leaving the sugar crystals we all know and love as table sugar. Now that you know where your candy comes from, let’s use some sucrose to make a treat.

How to Make Rock (Sugar) Candy

Rock candy is pure, crystallized sucrose, and you can make it at home. This will take one to two weeks, so get started now if you want to give it to someone special for Valentine’s Day.

You will need

  • 1 cup water
  • 3 cups sugar, plus about a spoonful extra to coat the skewers
  • Food coloring (optional)
  • Flavoring (optional)
  • Bamboo skewers
  • Very clean, heat-resistant drinking glasses or glass jars (like Ball or Mason jars)
  • 2 clothespins
 Tools and ingredients for making rock sugar candy laid out on the kitchen counter.

All the ingredients for the solution are assembled and ready to go. Note: the flavoring pictured here is not the best to use, because it contains alcohol. Use an essential oil for better results.


First, assemble the hardware. Cut the bamboo skewer to 6–8 inches, depending how long you want it. Attach two clothespins to one end. They will rest on the edges of your glass, suspending the skewer straight down in the glass without allowing it to touch the sides.

Cut a piece of paper towel with a hole in the center. This will go over the top of your glass to prevent dust from settling on the surface of the solution. Remove the paper towel and skewers; you’ll reassemble this after you’ve poured the solution in the glasses.

 Glasses and skewers set up for making rock sugar candy.

Suspend the skewers using one or two clothespins as pictured here, and be ready to cover loosely with a piece of paper towel like the glass shown in the middle.

Important tip: The directions I followed (from a reputable source) instructed me to moisten the end of the skewer with water and roll it in some sugar to “seed” the formation of new crystals. When I tried this, the sugar crystals all fell off the skewer the minute I put them into the solution. Crystals will not grow on a bare skewer. What did work was dipping the skewer into the sugar solution (which you are about to make) and then rolling it in sugar. This kept the tiny sugar crystals stuck on the skewer and allowed larger crystals to grow.

Making the sugar solution. Pour 1 cup of water in a saucepan and heat to boiling. Then turn the heat to low. You do not want to boil the water after you have added sugar, or you will make a syrup that is stable and will not yield crystals. Add the 3 cups of sugar gradually, and stir to dissolve. Push down any crystals that form on the sides of the saucepan during heating to dissolve in the water. This takes some time! Your final solution should be clear—not cloudy at all—and you should not see any crystals.

 Green-dyed rock sugar candy solution in a Mason jar.

You can choose to pour the liquid into two small glasses or one larger jar.

If you want to color or flavor your candy, now is the time. Add 2 to 3 drops of food color and/or 1/2 tsp of food-grade essential oils (like peppermint), and stir in thoroughly. Avoid using alcohol-based extracts like the bottle you see pictured in the blog. I’m not sure if this caused a failure during one of my trials, but I can say with certainty that I had better results when I used a flavoring oil.

Dip the end of the skewer a few inches into the solution and remove. Let the excess sugar water drain into the pot, and then roll the sticky end in dry granulated sugar to coat evenly. Set aside.

Pour the warm solution into the glass container(s), and fill to the top. With this recipe, you will get about 3 and 1/2 cups of solution, which will fill one jar or two glasses. You can scale the recipe up if you want more.

 Rock sugar candy skewers.

After about eight days, you can see the cube-shaped sugar crystals on these skewers. The longer you leave them in the solution, the larger the crystals will grow.

Carefully lower the sugar-coated skewer into the solution, holding it in place with the clothespins. Cover lightly with the paper towel and place it in a safe location where nothing will bump it or land in it for at least one week—two weeks if you want larger crystals. Do not totally seal your glass or jar. The water needs to evaporate for the sugar to come out of solution and crystalize on the skewer. If all goes well, then over the next week you will see large crystals forming only on the skewer.

Got candy? Remove the skewer and drain the syrup. Eat immediately, or allow to dry, wrap in plastic, and save for later. Now that is what I call cultivating the power the plants!

One more thing: You can use string instead of a stick. Tie a small weight on the bottom and tie the top to the a pencil balanced on top of the glass so that the string hangs in the liquid.

 A weighted string coated in rock sugar crystals.

The string was weighted with a metal nut so it would sink into the solution.

While you are waiting for your sucrose to crystalize, let’s contemplate where it came from.

Sugar from Plants

You probably know that plants harness energy from the sun to convert water and carbon dioxide into sugar and oxygen in a process we call photosynthesis.

 diagram of a plant showing carbon dioxide and light energy entering the plant leaf andwater entering through the roots, while glucose is formed in the leaf and oxygen is released into the air.

This basic diagram shows photosynthesis in action.

The product of the reaction is a sugar called glucose, which is chemical energy that a plant can use to build plant cells and grow. The formula looks like this:

6CO2 + 6H2O (+ light energy) C6H12O6 + 6O2.

Translated, it means that inside plant cells, six carbon dioxide molecules and six water molecules combined with energy from the sun are converted into one sugar molecule and six oxygen molecules.

Glucose molecules are combined to form more complex sugars. Sucrose, or table sugar, has a molecular formula C12H22O11.  It looks like two glucose molecules stuck together, but missing one oxygen and two hydrogen atoms (or one water molecule).  

 Sucrose molecule.

This sucrose molecule looks good enough to eat!

 Sugar cubes.

Just kidding. It looks better in normal scale.

As I mentioned earlier in this post, plants are the only thing on earth that can make sugar. Through modern chemistry, food scientists have figured out how to extract and modify plant sugars more efficiently. They have also developed different kinds of sweeteners, because the food industry is always striving to develop less expensive ways to satisfy our craving for sweets, as well as supply alternative sweeteners for different dietary needs. Some sugars you may see on food labels include dextrose (which is another name for glucose), sucrose, fructose, high fructose corn syrup, maltose, and sucralose. All of these “natural” sweeteners were processed from plants, even though they do not exist without help from a laboratory.

Have you noticed that all of these sugars, including the sugars in plant cell wall structures, have names that end in “ose”? That is no accident. The suffix “ose” is the conventional way chemists identify a substance is a sugar. Go ahead, share that information at your next party as you consume goodies made from plant sugars. Having some chemistry facts at your sticky fingertips makes you sound smart while you’re nibbling on sweet treats.

 Fresh produce in a wicker basket.


Please enjoy sucrose crystals responsibly, as part of a balanced diet that includes forms of sugars closer to their origins. (In other words, eat fruits and vegetables, too.) And remember to brush your teeth!

©2014 Chicago Botanic Garden and

Planting the Future

Plant Science and Conservation - Tue, 02/04/2014 - 11:33am

David Sollenberger is building a time machine. He is capturing the prairie of today so that it can appear again in the future.

Moving about the Dixon National Tallgrass Prairie Seed Bank Preparation Laboratory at the Chicago Botanic Garden, Sollenberger works with a combination of everyday and high-tech tools. Brown paper bags filled with seeds scatter the windowsill, while metallic seed-drying machines with dials, switches, and gears line a wall. A long, stainless steel work table in the middle of the room is often surrounded by a team of focused volunteers.

The pulse of this active lab is the heartbeat of the Garden’s Seed Bank — a living collection of plant seeds reserved for potential future plantings.

 David Sollenberger in a large, walk-in freezer room. He's wearing winter gear and a knit cap.

David Sollenberger files a seed packet in the Garden’s vault.

“Tallgrass prairie is a globally threatened ecosystem, and we’re working hard to preserve what is left,” said Sollenberger, Seed Bank manager at the Garden.

While the prairie was once visible from horizon to horizon in the Midwest, it is now reduced to small, disconnected pieces of land that struggle to survive. While many of those remnants are protected from threats such as continued development, they remain fragile due to their disconnect from other natural areas and impending threats such as climate change. Seeds preserved in a seed bank can be used to create new habitat, or used to enhance existing areas in the future.

Prairie Protocol

The Garden began its Seed Bank as a part of an international effort led by the Millennium Seed Bank and the Bureau of Land Management’s Seeds of Success program. Together with partners from across the globe, they banked 10 percent of the world’s flora by 2010. Then, the Garden chose to continue to save seeds regionally, along with Seeds of Success.

 A view through the window into the prep lab, where staff and volunteers are sorting seeds.

Peek into the Seed Bank Preparation Laboratory on your next stroll through the lobby of the Daniel F. and Ada L. Rice Plant Conservation Science Center to see the seed savers in action!

During warmer months, Sollenberger and a small group of contractors individually go into the field to gather seeds from a list of 544 target species. Each year they visit parts of the 12 interconnected ecoregions of the tallgrass prairie system, including wetlands, meadows, and prairies. Although there are more than 3,000 prairie species in the Midwest alone, Garden scientists identified a critical list of plants to focus on that are important species within the habitats they represent.

Following collection protocols established by the Millennium Seed Bank, they try to collect seeds from at least 50 plants in a population, which allows them to capture up to 95 percent of the population’s genetic diversity. When they do, they can share a section of the collection with national seed banks for backup storage.

However, due to the small size of many prairie remnants, there are sometimes fewer than 50 individual plants of a species in a population. In that case, Sollenberger explained, they collect along maternal lines, which means that seeds are collected separately from each plant. This results in a systematic representation of the genetic diversity of a species within a population.

Time Traveling

 Closeup of a volunteer's hand moving seeds from a bulk pile to a smaller pile with tweezers.

Seeds are counted for packaging.

During winter in the laboratory, the collected seeds are first sorted and cleaned. It can be a meticulous and time-consuming process. But Sollenberger uses a number of techniques to add efficiency.

To sort viable seeds (those that hold an embryo inside) from those that are empty hulls, the team loads a batch into a large, clear cylinder with a motor-run fan called a column blower. When the seeds are blown about within the container, the heavier ones ­fall to the bottom while the lighter ones rise to a top shelf and can be disposed. They also use an X-ray machine to look inside a sample of seeds to determine what percentage is filled and potentially viable.

For seeds from the Aster family, goldenrods, and milkweeds, the team must first remove the silky hairs, or pappus. First, seeds are rolled on a rubber mat to loosen the pappus.

Then, they are run through a typical Shop-Vac that separates the pappus from the seeds. By using this process, “we’ve been able to improve the quality of the seeds,” noted Sollenberger. “It decreases the volume of seeds so there is less packaging, which allows for more space in the seed vault, and it improves our ability to separate light, non-viable ‘empty’ seeds and other light extraneous plant materials (chaff) from heavier, potentially viable ‘filled’ seeds.”   

 A hand with paper towel rolls seeds on a baking mat.

Seeds are rolled on a mat to remove the pappus.

 A hand pulls seed pappus "lint" from the shop vac's filter.

A filter inside the vacuum separates the pappus from the seed.

Throughout this process, seeds are stored in the dryers. There, they are dried to 15 percent humidity, which is critical for their successful storage at minus 20-degrees Celsius. Using this process, the majority of Midwestern prairie seeds can be stored for up to 200 years.

Early in his career, David Sollenberger helped to build the Garden’s Dixon Prairie. Learn more about his work. Bring your own seeds to our annual Seed Swap, Sunday, February 23.

Another few months of seed sorting await Sollenberger and his team, but he is already thinking of spring. “We take a breath in springtime when everyone else is busy,” he chuckled. It is then that he likes to visit  McDonald Woods to soak in the beauty of a truly native natural area, before heading out in the summer to collect the next batch of seeds.

©2014 Chicago Botanic Garden and

Culture, Climate, and Rubber: Reflections on Xishuangbanna

Plant Science and Conservation - Thu, 01/30/2014 - 1:48pm

Why go all the way to China to talk about climate change, when there are plenty of conversations to have here in the U.S.?


Xishuangbanna shares border land with Myanmar and Laos.

Returning from a week at Xishuangbanna Tropical Botanical Garden for their Third International Symposium focused on “The Role of Botanic Gardens in Addressing Climate Change,” I’m struck both by the complexity and difference of the Chinese culture from ours, and by how many of the same challenges we face.

These challenges are global, and to solve them, we need to take a global perspective. Though the United States and China are in very different stages of economic development, we are the two leading emitters of greenhouse gasses—and we must lead the way in reducing our impact.

Xishuangbanna Tropical Botanical Garden is located near the village of Menglun in the Dai Independent Prefecture of Xishuangbanna in Yunnan province in China, which shares 619 miles of borderland with Myanmar and Laos.

The area is a lush, tropical paradise, and does not seem at all affected by climate change, but it is a concern: the tropical areas of China—only 0.2 percent of its total land mass—represent more than 15 percent of the biodiversity in the country.

 Peach-colored epiphytic orchids wrap their roots around a branch.

Native epiphytic orchids in Xishuangbanna

 A view up into an enormous strangler fig.

Strangler figs and other enormous tropical trees create a high canopy above the forest floor.

Biogeographically, Xishuangbanna is located in a transitional zone between tropical Southeast Asia and subtropical East Asia, so the climate is characterized as a seasonal tropical rain forest, with an annual average temperature of 18-22℃ (64.4-71.6℉), with seasonal variation. At about 20 degrees north of the equator, it is just on the northern edge of what is considered the tropics, though it does follow the rainy/dry seasonal patterns—May to October is the rainy season and November to April is the dry season. During my stay, they were experiencing weather somewhat colder than usual, with nighttime temperatures in the upper 40s and daytime temperatures in the low 60s. Earlier in the month, it was only in the upper 30s, but still far warmer than here in Chicago!

 A view of the Mekong River Valley

A view of the Mekong River Valley

The vistas were breathtaking. This is a mountainous region, covered with lush tropical and semitropical plant life, wild bananas, lianas (long-stemmed, woody vines), tualang (Koompassia), and Dipterocarpaceae trees—some of which are more than 40 meters tall!

When I arrived on January 10, I noticed that many of the mountains were covered with what looked like vast areas of rust-colored trees. Rust-colored, I learned, because of a recent cold snap that damaged the leaves of the local monoculture: rubber trees.

 View of Menglun Village, China.

A view of Menglun Village from Xishuangbanna Tropical Botanical Garden. The Mekong River tributary is in the foreground; rubber trees cover the hills in the background.

Rubber is the new thing in Xishuangbanna. Over the past 40 years, rubber trees have been bred for cooler climates, so production has moved northward from the true tropics to areas like Xishuangbanna. This has had enormous benefits for the local Dai population. Subsistence farmers in the past, they have been able to substantially improve their town infrastructure and their standard of living. But as rubber plantations expand, the ecosystem here is increasingly threatened, with only scattered fragments of untouched tropical forest left. While not directly related to climate change, the impacts of rubber were extensively discussed among conference attendees, because climate change exacerbates other environmental stresses like the fragmentation caused by the rubber plots.

 The bark is stripped from a rubber tree. The sap is gathered and turned into rubber.

Not originally a local crop, rubber has become a primary crop of the area.

This seems to me to be a constant tension globally—the competing interest between economic development and conservation—and we’re still looking for the balance. In the United States we continue to have this debate, but around fracking and oil production rather than agriculture. Economic growth at the expense of the environment seems reasonable until we suddenly reach the point where the ecosystem services we depend on to live—clean water and air, food, medicine, etc.—are suddenly in jeopardy, either through direct human action or indirectly though other anthropogenic causes. And that brings us back to climate change.

Climate change is not an easy or comfortable topic of conversation.

Climate change is scary, politically (though not scientifically) controversial, abstract, and easy to ignore. It challenges us as individuals and organizations to rethink our priorities and choices, and to recognize that we may have to change the ways we do things, and how we live our lives, if we are to really address the problem. It is for these reasons, I think, that it generally is not a topic that botanic gardens have focused on when we develop our education or outreach programs. Internationally, gardens are finally beginning to work towards changing that, by building staff capacity to teach about climate change and by integrating climate-change education into existing and new programs.

Where better to understand and communicate how climate change will impact the natural world than at a botanic garden, where we can actually observe its impacts on plants?

The purpose of the conference was to bring together a group of international botanic garden researchers and educators to share their activities around climate change and to think broadly about how botanic gardens can and should use their resources to support movement towards a more sustainable society, as well as how we develop mitigation and adaptation strategies both for conservation purposes and human survival.  Almost 20 countries were represented at the conference, though disappointingly, I was the only U.S. attendee.

 Group shot of a handful of conference attendees around a low table, eating dinner.

Many of our dinners were in the amazing local Dai cuisine—a real treat!

My particular area of expertise is environmental education, so experiencing tropical ecosystems directly, which there obviously isn’t the opportunity to do here in the Midwest, truly amazed and inspired me, and renewed my passion for communicating the wonder of nature to all the audiences that the Chicago Botanic Garden serves. It also drove home the real challenge we have to protect these ecosystems as the climate changes. In our discussions and in the sessions, we really focused on looking for solutions—action items—immediate and long term, that we as researchers and educators, and collectively as botanic gardens, could do to make a difference. 

After dozens of sessions on research and education (everything from paleobotany to using neuroscience to better tailor climate- education messaging—really fascinating!), and discussion in targeted working groups, we produced the Xishuangbanna Declaration on Botanical Gardens and Climate Change

In the education group, we took a multifaceted approach to the challenge—to really make a difference we need to increase our own capacity to communicate about climate change, more effectively engage our visitors in that discussion, and reach out to political, social, religious, and economic leaders to support the development of policies and practices that address the impacts of climate change on plants and society. It sounds like a herculean task, but if we each take one part of the job, I believe we can do it together. For example, here at the Chicago Botanic Garden we’ve stopped selling bottled water, use electric hand dryers rather than waste paper, are committed to LEED (Leadership in Energy and Environmental Design) certification for new building construction, and continue to look for other ways to reduce our carbon footprint.

It’s important that as institutions, gardens begin to “live the message” by implementing appropriate sustainability policies at our own institutions.

The entire declaration provides what I think is a concise, yet comprehensive, outline of how botanic gardens can use their strengths to address the very real challenge of climate change: through education, by taking meaningful steps to engage all our audiences; through research, by better understanding how climate change is affecting our environment; and through conservation, by protecting biodiversity and the other natural resources on which we depend.

 Chinese temple.

Highlights outside the symposium included visiting this temple and the local market, and taking a canopy walk.

 Women at market with giat 9-foot stalks of harvested sugar cane.

Sadly, raw sugar cane available in the local market would not fit in my suitcase to go home.

 The author standing at a joint in a canopy walk path.

The signs on this walk warn that there is no turning around on the path. It’s not hard to see why.

 A view back across the canopy bridge reveals how high the path is in the trees.

SO high up in the canopy, but the hills are still taller.

While there is no one “one size fits all” agenda or program that will work for every garden or every individual, I think there is a common approach that can be taken—gardens collectively need to develop a consistent message and mobilize our networks to communicate about climate change and its impacts. Gardens, along with our members, visitors, and patrons, have the capacity and the opportunity, if we will only take it, to inspire the broader community to act now for a better future. Join us.

©2014 Chicago Botanic Garden and

Wired Nature

Plant Science and Conservation - Mon, 01/13/2014 - 2:09pm

As winter winds disperse prairie seeds and fragrant pinecones tumble down, Bianca Rosenbaum is busy collecting. As much as she would love to forage through the seasonal natural materials outside of her office at the Chicago Botanic Garden, that’s not what she is after these days. Rather, she is gathering data.

 Bianca Rosenbaum at her desk.

Rosenbaum manages data from her colorful office.

Seated at her desk in the Daniel F. and Ada L. Rice Plant Conservation Science Center, Rosenbaum taps away at her computer’s purple keyboard. The Garden’s conservation science information manager is busy finishing her masterpiece—a searchable collection of visual and numeric plant data. The new product is a one-stop-shop for information previously housed in three separate databases and accessible by few.  

Named the Science Collections database, the project centralizes the Garden’s data on seed collections, herbaria, and plant DNA. For the first time, the information is accessible online by anyone from international scientists to curious children.

“We saw this great opportunity to combine our databases and be able to cross reference collections,” she said. “It’s been very exciting. It’s one of my biggest, most challenging projects. It feels extremely rewarding.”

Since she began working at the Garden in 2002 as an expert in Microsoft Access, Rosenbaum has overseen the safekeeping of the data in all three of these areas as well as other Garden research collections. In just a few years, the way the information was stored and managed became outdated as technology progressed. She was thrilled with the opportunity to advance its management system.

When the Science Collections project began four years ago, one of her first tasks was to identify data used by all three databases and merge them into common tables to eliminate repetition and guarantee standardization. The result was a complicated set of linked tables that comprise the structure for the final product—called a relational database.

 Collections database search results screen.

A search in the Science Collections database reveals merged information about each species.

She then merged all of the data on each species. Now, rather than going to different databases to find all of the herbarium, seed, and DNA information recorded about a plant, it can be found in one place. 

Rosenbaum then worked with the Garden conservation GIS lab manager, Emily Yates, to add a spatial component to the data by mapping plant locations, which are linked to each collection record. Lastly, she built a web page to serve as a portal from the database to the internet.

Data from the Garden’s Nancy Poole Rich Herbarium are mainly visual, with 17,000 images of pressed plants alongside notes about location and related details. Information from the Dixon National Tallgrass Prairie Seed Bank includes high-resolution images of seeds from 2,600 species. The program also includes notes about whether the Garden houses material that may be accessed for DNA sampling for a given plant. The records include information on all classifications of regional plants, and some international. Only those labeled as threatened or endangered are not shown on a map.

 Page from the herbarium with Liatris aspera sample and data.

Liatris aspera (Herbarium acc. 4439)

“This job has totally changed my outlook,” said Rosenbaum, who had no real interest in botany before coming to work at the Garden. “I feel very fortunate that I’ve been here and I’ve been able to combine both the tech world and the environment.”

As a child, she grew her love of technology with encouragement from her parents—an engineer and electronic assembler. She went on to study computer engineering in college, and gained work experience with coding and data management. As a Garden employee, she has coupled those computer skills with a new set of plant-related skills. She is now comfortable with plant names, discussing scientific processes, and even growing her own vegetable garden at home.

Although she spends much of her work day glued to her computer screen, Rosenbaum does find time to look out her window, or step outside to connect with her subject matter. “I think it’s very easy to not notice this world when you are in the tech world, or the business world,” she said. “Now I can connect the two and know what it is I am working on and see what I am working to protect and conserve.”

Rosenbaum often strolls the Waterfall Garden in warm months, but she especially looks forward to spending time in the peaceful Dixon Prairie.

The recently launched database is now open to exploration at Check back in coming months for Rosenbaum’s forthcoming addition of advanced search options. 

©2014 Chicago Botanic Garden and

Make a Grapefruit Bird Feeder

Youth Education - Tue, 01/07/2014 - 12:50pm

My daughters love fresh grapefruit, and winter is the season when this fruit is at its best. Instead of throwing away the rind, we decided to make a bird feeder. This is a great winter project for the family.

 The supplies needed for the project.

The grapefruit sections have been cut and eaten; the rind is ready to become our bird feeder.

To make a grapefruit bird feeder you will need:

  • Half a grapefruit rind (you can also use an orange)
  • Three pieces of yarn, each cut about 18 inches long
  • A knife, skewer, pointed scissors, or other sharp tool
  • Birdseed

First, eat the grapefruit and drain the remaining liquid. Then, use the skewer or knife to poke three holes in the grapefruit. They should be about half an inch from the top edge and spaced evenly around the circumference. (Some people do this with four strings, but I find that using three strings makes it easier to balance the fruit.)

Push a piece of yarn through each hole and tie it off.

 Skewering the grapefruit rind.

Hold the grapefruit firmly with one hand while you poke the skewer through the rind. Be careful not to poke your finger!

 Tying yarn to the grapefruit to hang it.

Pull 2-3 inches through the rind and tie the short end to the longer strand.

Hold the grapefruit up by all three strings and adjust the length of the strands so the fruit is not tipping. When it is balanced, knot the strings together about 4 or 5 inches from the top. (The ends will probably be uneven, and that is all right.) Make a loop knot with those top ends, so you will be able to hang it from a branch. 

 The final product.

Our grapefruit bird feeder is balanced, full of seed, and ready to hang outside.

Finally, fill the fruit with birdseed and hang it outside for your feathered friends to enjoy. If you like, you can add a little suet, but you may find it doesn’t stick well to the wet fruit. Here in the Chicago area, you’ll probably find that most of your winter guests are black-capped chickadees, nuthatches, dark-eyed juncos, common redpolls, and downy or hoary woodpeckers, who balance their primary diet of insects and grubs with bit of suet and sunflower seeds.

One more thing: Make sure it’s tied to the branch firmly so that your local (determined) squirrels — who will also find this bird feeder appealing — don’t knock it down.

Don’t worry if you don’t have any visitors the first few days after you’ve placed your feeder. It can take up to two weeks for birds to discover their new food source, but once they do, they tell all their friends in the neighborhood.

 Grapefruit birdfeeder hung from a snow-covered fir.

The final product is ready for visitors.

What is birdseed?

You probably know that if you plant birdseed, you won’t grow a bird. And there is no such thing as a birdseed plant. So what plants make birdseed? What we call “birdseed” most commonly comes from two sources: millet, which is a grass, and sunflower. Other seeds used to feed birds include thistle, safflower, cracked corn, and sorghum seed, which is also called milo. Some birds have a preference for certain kinds of seeds, so bird lovers stock their feeders with seeds to attract their favorite birds and keep them visiting the feeder.

After you hang your bird feeder, take some of the seed and plant it to see what grows. Maybe you can grow your own food for the birds this year!

©2014 Chicago Botanic Garden and

Christmas Tree Taxonomy

Youth Education - Sat, 12/14/2013 - 8:15am
 A student in class is examining evergreen needles.

Quick quiz: is this boy holding a twig of conifer, evergreen, or both?

Every winter, as a public garden, the Chicago Botanic Garden turns its educational programming attention—as well as its decorations—to the only plants that stay green through the season: the evergreens. We teach class after class of school children how to identify different kinds of evergreens by their needles and cones.

It’s a lesson in sorting and classifying plants—in other words: taxonomy. 

Conifer vs. Evergreen

Every year we remind students of the meanings of the words “evergreen” and “conifer”—they are not the same thing!—and every year, someone is confused. I blame Christmas trees.

 Venn diagram showing a christmas tree in the intersection of the sets "evergreens" and "conifers."

The “Christmas Tree” intersects both of the sets “evergreens” and “conifers”—it’s both!

First, it’s important to understand that evergreens are any plants that remain green through the winter, like pine, spruce, fir, and Douglas fir. Conifers, on the other hand, are a classification of trees that produce seeds inside cones. These trees include pine, spruce, fir, and Douglas fir. Wait a minute…those are are the same trees!

You see, the problem is that our Christmas trees tend to be both evergreen and conifer, and as a result, many of us have forgotten the difference. To help us illustrate the definitions of the two terms, let’s look at some evergreens and conifers that do not fall into the intersection of those groups.

 Charlie Brown and Snoopy with a sad-looking, needle-free tree sporting a single ornament.

Charlie Brown’s tree might have been a bald cypress.

One conifer that loses its needles, and therefore is not an evergreen, is the bald cypress. These can be very attractive when covered in snow. (The bald cypress trees growing in the Heritage Garden have been pruned at the top and look like candelabras.) The needles on these trees change color in fall—the same way deciduous trees like maples and oaks do—and drop to the ground, making them look, well, bald.

Boxwoods and rhododendrons are woody plants that keep their green leaves all winter, but they do not produce cones. Boxwoods are occasionally used in wreaths and can be found in many places around the Garden.

 Closeup of a bald cypress branch in golden fall color.

Bald cypress (Taxodium distichum) is called “bald” for a reason—its needles change color and fall in autumn just like deciduous trees such as maples and oaks.

 Boxwood in the Japanese Garden.

Boxwood in winter in the Malott Japanese Garden: these true evergreens may yellow a bit with winter, but keep their foliage.

Now here is where things actually do get confusing. Female yews produce a bright red “berry” that might make you think they are just evergreens. Actually, when you take a close look at the hard core at the center of this berry, you would see small, closed scales like those on any other “pine” cone. Yep. Juniper “berries” are also modified cones. That means yew and juniper are both evergreen and conifer.

 Closeup of yew berries showing seed/nut inside the berry.

Yew berries (Taxus baccata)
Photo by Frank Vincentz, via Wikimedia Commons

So call your Christmas tree an evergreen or a conifer—you will be correct either way. But it’s worth remembering what the two terms mean. Recognizing how things are alike and different is the driving force behind taxonomy and is also fundamental to understanding the natural world.

Have a wonderful holiday season!

©2013 Chicago Botanic Garden and


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