Indoor Plant Care Checklist

Indoor Plant Care
June, June, June, June, June, June

Amaryllis plants should be placed in morning sun (preferably outdoors), watered regularly, and fertilized every 2 to 3 weeks with a general purpose, liquid fertilizer.

Indoor Plant Care
September, September, September, September, September, September

Geranium SeptemberCuttings from favorite or unusual varieties of annuals such as geraniums, coleus, begonias, and impatiens can be taken this month, potted up, and brought inside to a south-facing window. Some tender unusual container plants can be brought inside as whole plants — hebe, black mondo grass, mandevilla vine, and certain small geranium plants are a few. Many gardeners prefer to repot the plants and change the soil to a fresh, lightweight, soilless mix at this time.

Houseplants that have spent summers outside should be monitored in the event of a premature frost. Check plants carefully for any sign of insect or disease before bringing them indoors. Gradually reintroduce these plants to indoor conditions. Consider repotting and changing soil at this time. Do not change size of pot until spring.

Amaryllis bulbs that have summered outdoors must begin their dormant period. Remove bulb from container and shake off all dirt. Cut back all foliage, whether it is yellow or green, and set bulb on its side in a cool, dark room for several months until new growth appears.

To create a winter herb garden, dig up selected herbs such as thyme, basil, rosemary, or oregano. Repot in smaller pots, change soil to soilless mix, and cut plants back. Gradually introduce plants to indoor conditions before bringing inside to a sunny windowsill. Herbs will put out new growth, but it won’t be as vigorous or as tasty as the summer crop.

Indoor Plant Care
October, October, October, October, October, October

Houseplants should be gradually acclimated to indoor conditions and brought inside before the Chicago area’s first anticipated frost of October 15. Monitor all plants carefully for insects or disease before bringing them in. Discard seriously diseased plants. Sequester new plants from those that grow indoors year-round to prevent disease or insect contamination.

Indoor Plant Care
November, November, November, November, November, November

orchid NovemberPlants brought indoors this fall might exhibit temporary “transplant shock” in their new environment due to changes in light and temperature. Sun-loving houseplants might suffer during cloudy winter season. If possible, consider supplemental artificial lights. Avoid overwatering houseplants. Cut back on fertilizer in general, except for plants intended to bloom all winter, such as miniature roses or geraniums.

Most houseplants appreciate a 10- to 15-degree difference in day and night temperature. Monitor plants for early signs of problems. When indoor heat is turned on, natural humidity disappears. Try to wash plants occasionally in a warm shower. Humidifiers and pebble trays can help raise humidity.

Pot up pretreated bulbs, such as amaryllis, paperwhite narcissus, and others, for holiday blooms.

Continue to fertilize orchids with very dilute orchid fertilizer until they set flower buds. Monitor orchid foliage to be sure it doesn’t scorch from exposure to direct southern sun.

Extra hardy bulbs not planted outside this month can be potted up and forced for indoor blooming. Plant bulbs in wide, shallow pots in a soilless mix. Large bulbs are planted side by side with just their tips showing. Little bulbs are planted with ½ inch of mix covering them. Water well and place pots in a refrigerator, cold frame, garage, or shed where the temperature remains between 35 and 40 degrees Fahrenheit. If storing in a refrigerator, cover pots with plastic wrap and avoid storing ripening fruit in same area. Some fruit releases ethylene gas, which inhibits flower formation. Major bulbs require 12 to 14 weeks of cold storage; little bulbs require a few weeks less. When pale yellow sprouts begin to show, pots can be brought out of cold storage into a bright but quite cool room (55 to 65 degrees F.) for about two weeks. As flower buds begin to develop, bring pots into a warmer room but avoid direct sunlight. Water as needed.

Indoor Plant Care
December, December, December, December, December, December

Houseplant DecemberMonitor houseplants for insect problems that often occur when plants become stressed due to insufficient light, overheated rooms, or improper watering and fertilizing techniques. New houseplants or gift plants can also harbor pests. Isolate these plants before adding them to your collection. Pests to look out for include the following:

  • Spider mites — Look for webbing in leaf axils, stippled foliage and weak, off-color leaves. Mites are often difficult to see without a lens.
  • Scale — Characteristic sticky, clear honeydew is produced on leaves by these small, immobile, rounded insects usually found on stems and veins of leaves.
  • Mealybugs — Easy to spot, these insects resemble crowds of tiny cotton puffs.
  • Whitefly — Whiteflies are a major problem in many greenhouses because they can quickly move to neighboring plants. Look for tiny, white, mothlike insects often found on the undersides of leaves.
  • Fungus gnats — The adult black gnats fly around the plant but do no damage. The immature larvae in the moist soil can chew plant roots. They are often a problem in overwatered plants or overly moist flats of seedlings.
Indoor Plant Care
January, January, January, January, January, January

Maidenhair fernMost houseplants require less water and much less, if any, fertilizer, because they slow their growth during this semidormant winter period. Succulent plants, such as cacti and jade plants, are in a winter dormancy and require bright light but very cool conditions with no water for up to two months. Overwatering will create soft brown patches on stems and foliage.

Monitor houseplants for insect problems that often occur when plants become stressed due to insufficient light; overheated, stuffy rooms; or improper watering and fertilizing techniques. New houseplants or gift plants can also harbor pests. Isolate these plants before adding them to your collection. Pests to look out for include the following:

  • Spider mites — Look for webbing in leaf axils, stippled foliage, and weak, off-color leaves. Mites are often difficult to see without a lens.
  • Scale — Characteristic sticky, clear honeydew is produced on leaves by these small, immobile, rounded insects usually found on stems and veins of leaves.
  • Mealybugs — Easy to spot, these insects resemble crowds of tiny cotton puffs.
  • Whitefly — Whiteflies are a major problem in many greenhouses because they can quickly move to neighboring plants. Look for tiny, white, mothlike insects often found on the undersides of leaves.
  • Fungus gnats — The adult black gnats fly around the plant but do no damage. The immature larvae in the moist soil can chew plant roots. They are often a problem in overwatered plants or overly moist flats of seedlings.

Herbs growing on windowsills, as well as smaller houseplants, can benefit from spending a few months under artificial lights to supplement the diminished natural sunlight. Homeowners can construct a light table using two 40-watt fluorescent lights, one cool and one warm, for each foot of shelf space filled with plants. Try to group plants with similar heights together so the light fixture can be set as close to the plants as possible — a few inches above the plants is best. Keep the lights on for 14 to 16 hours a day.

Start seeds for early spring annuals requiring a long lead time before being set out in the garden. Follow directions on individual packets as to which types of seeds require bottom heat, light or darkness in order to germinate. Some seeds might require a short period of chilling before being sown. Cool-season annuals (larkspur, snapdragon, English daisy, ranunculus, monkey flower, pansy, annual poppy, forget-me-not, edging lobelia) can be planted outside in the garden by the second week in April after the small plants are hardened off. This may require starting seeds 14 weeks ahead in order to have blooming plants ready for outside planting.

Sow seeds in fiber pots or trays, using a premoistened, soilless or seed-starting mix. Sow large seeds in slightly indented rows and cover lightly with a thin layer of the mix. Finer seeds may be broadcast directly on top of soil. Some types of seeds will require a glass or plastic cover to provide supplemental humidity. Water seeds from the bottom or use a fine mister to keep the soil moist. Most seeds require a warm, bright location out of direct sun to germinate. Ventilate covered seeds daily, especially in bright conditions.

When germination occurs, gradually increase light levels. When two sets of true leaves develop, transplant small seedlings to a larger fiber pot that contains a slightly coarser, "growing-on" mix. Continue to water from the bottom to encourage strong root development. Begin fertilizing with quarter-strength 10-10-10 solution. As the plant grows larger, switch to a half-strength solution once a week.

Harden plants off approximately seven to 10 days before setting them out. Take them outside for a few hours a day and back in again at night. Gradually increase the time spent outside until they are ready to be planted in containers, window boxes, or garden beds.

Indoor Plant Care
February, February, February, February, February, February

Amaryllis FebruaryContinue to care for amaryllis following their flower display. Allow all stems to wither before cutting them off the bulb. Keep the pot in a bright, warm location, out of direct sun. Water the plant as needed. The green, strappy leaves will continue to grow. When all danger of frost has past, take the pot outside to the garden and keep it in a location protected from afternoon sun. Fertilize the bulb every 10 to 14 days with a liquid 10-10-10 or 15-15-15 mix. This fertilizer helps refuel the bulb for another season’s flower show.

In February many houseplants might show signs of stress caused by light deprivation, overwatering, insufficient humidity, and overheated indoor air. Stressed plants are more likely to develop insect and disease problems, so monitor your plants for early signs of trouble. New houseplants or gift plants may also harbor pests, and these plants should be isolated before joining other plants in your indoor garden. Pests to look out for include the following:

  • Spider mites — Look for webbing in leaf axils, stippled foliage and weak, off-color leaves. Mites are often difficult to see without a lens.
  • Scale — Characteristic sticky, clear honeydew is produced on leaves by these small, immobile, rounded insects usually found on stems and veins of leaves.
  • Mealybugs — Easy to spot, these insects resemble crowds of tiny cotton puffs.
  • Whitefly — Whiteflies are a major problem in many greenhouses because they can quickly move to neighboring plants. Look for tiny, white, mothlike insects often found on the undersides of leaves.
  • Fungus gnats — The adult black gnats fly around the plant but do no damage. The immature larvae in the moist soil can chew plant roots. They are often a problem in overwatered plants or overly moist flats of seedlings.

If winter sunlight has been minimal, foliage plants as well as herbs and all flowering plants might require artificial light to supplement the diminished natural sunlight. A light table would require two 40-watt fluorescent tubes, one cool and one warm, for every foot of shelf space filled with plants. Group plants with similar heights together so the fixtures can be placed just a few inches above the plants. Keep the lights on between 14 and 16 hours a day.

Continue to start seeds for spring- or summer-blooming annuals, vegetables, and perennials. Follow the directions on individual packets as to which types of seeds require bottom heat, light, or darkness to germinate. Some seeds might require a short period of chilling before being sown.

Sow seeds in fiber pots or trays using a premoistened soilless or seed-starting mix. Sow large seeds in slightly indented rows and cover them lightly with a thin layer of the mix. Finer seeds may be broadcast directly on top of the soil. Some types of seeds will require a glass or plastic cover to provide supplemental humidity. Water seeds from the bottom, or use a fine mister to keep the soil moist. To germinate, most seeds require a warm, bright location out of direct sun. Ventilate covered seeds daily, especially in bright conditions.

When germination occurs, gradually increase light levels. When two sets of true leaves develop, transplant small seedlings to a larger fiber pot that contains a slightly coarser "growing-on" mix. Continue to water from the bottom to encourage strong root development. Begin fertilizing with a quarter-strength 10-10-10 solution. As the plant grows larger, switch to a half-strength solution once a week.

Approximately seven to 10 days before setting out plants, harden them off by taking them outside for a few hours a day and back in again at night. Gradually increase the time spent outside until the plants are ready to be planted in containers, window boxes or directly into the garden.

Indoor Plant Care
March, March, March, March, March, March

Begonia MarchContinue to care for indoor flowering gift plants.

Azaleas require even moisture and bright light. Deadhead to keep plants blooming for four to six weeks. Azaleas can go outside to a partly shaded location after May 15, but must come back in before fall frost.

Primrose plants can be discarded after flowering or planted directly in shaded, well-drained garden area. They will go dormant during summer months and require heavy mulch to protect from summer heat and winter cold. Indoor-blooming tulip, daffodil, hyacinth, or crocus plants can be planted outside and treated like outdoor bulbs after they have flowered but there is no guarantee they will flower the following year.

Get a head start on summer-blooming bulbs and tubers by starting them indoors in moist, soilless mix. Plant Caladium (caladium), Colocassia (elephant ears), Begonia x tuberhybrida (tuberous begonia), Crocosmia (montbretia), Agapanthus (Lily of the Nile), Canna x generalis (garden canna), Polianthes (tuberose), Acidanthera (peacock orchid). Keep warm until new growth appears. Move pots into a sunny window or under grow lights if necessary. Move these pots outside when all danger of frost has passed, after gradually introducing plants to warm weather conditions.

Repot houseplants, including orchids, after they have flowered and if they have become rootbound. Increase pot size by one inch. Change the potting soil/fir bark but do not change the level at which the plant was situated in the pot.

Fertilize houseplants as they begin new growth. Try low dosages of organic fertilizers or a very dilute, balanced granular fertilizer rather than stronger formulas. Telltale white salt markings on terra cotta pots indicate overuse of fertilizer. Flush out soil of overfertilized plants with plain water.

Propagate houseplants. Softwood cuttings, leaf cuttings, air-layering, cane cuttings, or division may all be done this spring.

Start seeds of warm-season annuals and vegetables in a moist, soilless seed mix. These seeds are started six to eight weeks before the spring frost date of May 15. Transplant tiny seedlings into a "growing on" mix in slightly larger containers when they have two sets of true leaves. Gradually introduce small plants to outdoor conditions. They can be planted in containers or garden beds after May 15.

Indoor Plant Care
April, April, April, April, April, April

Seedlings AprilIf not done in late March, there is still time to sow seeds indoors for warm-season vegetables like tomato and pepper plants and summer-blooming annuals. Most seeds take six to eight weeks from germination to outdoor planting.

Continue to bring houseplants inside at night but outside during warm days. Most houseplants can remain outside when night temperatures are consistently 40 to 50 degrees. When in doubt, wait until mid-May before placing houseplants permanently in the garden.

If orchids have finished flowering, begin to fertilize regularly with a very dilute orchid fertilizer or use fish emulsion with every watering. Monitor closely for scale attack.

An Orchid FAQ: How to Repot
February

Talk around the Garden is all about orchids this month, with our first-ever Orchid Show opening on February 15. Among the many interesting orchid conversations, there is one question that gets asked repeatedly by gardeners of all skill levels: "How do I repot my orchid?"

Luckily, the answer for most orchids is, "It's easy."

PHOTO: Dendrobium Country Girl 'Warabeuta'.

Orchids should be repotted when new; every year or two; or when crowded roots push up and out of the pot.

Spring: time for a close-up.

Other than watering and occasionally fertilizing them, you probably don't look closely at your orchids all that often when they're not in bloom. Spring is the time to examine each plant with a critical eye to assess the need for repotting. It's also when you'll see the new growth that signals emergence from the dormant cycle—the best time for repotting.

Is it new? Holiday gift orchids or newly-purchased plants are often planted with sphagnum moss, which absorbs and holds water—creating prime conditions for orchid root rot. Repot all new orchids as soon as they're done blooming.

When was the last re-potting? Orchids need both the nutrients from the chunky, loose bark mix they're planted in and the air space in between the pieces. As the mix breaks down to particle size, it compacts the air spaces inside the pot—virtually suffocating your orchid's roots. Check the bark mix every spring and repot when you notice decomposition.

Is it crowded in there? While orchids prefer a small pot—weaving their roots through the compost as they grow—they eventually run out of room. That's when their roots push the plant up above the rim of the pot or reach out into the air, looking for breathing space—a sure sign that it's time to re-pot.

PHOTO: Bark chips.

Fresh bark mix is chunky and loose; decomposed mix fills in the air pockets that orchid roots need.

Gather a few supplies.

Repotting an orchid sounds complicated and exotic, but it's a simple process requiring just a few items:

  • Fresh bark mix. The mix matters: some typical store-bought mixes deteriorate far too rapidly. For high-quality mixes, Chicago-area orchid fans can travel west to Orchids by Hausermann's, an orchid nursery that carries several bark options—not to mention fantastic plants. Online orchid specialists offer more options, too.
  • A pot that's one size larger than the original, in case your orchid is ready to move up.
  • Pruners and/or a sharp pruning knife, sterilized in a 10 percent bleach solution.
  • Scissors or a razor blade for trimming roots and leaves.
  • Gloves to protect your hands from splinters and prickles.
  • A thin dowel or blunt knife for settling compost around the roots.

PHOTO: Healthy orchid roots.

Healthy orchid roots are white; pale green tips indicate new growth.

Get to the root of it.

Now comes the interesting part.

Remove the orchid from the pot. Roots can be potbound and sticky; first try "massaging" the pot to loosen the rootball. Not budging? Work a dull knife down and around the inside of the pot, then invert it and tap the pot on your work surface to remove.

Soak the roots. Examine the rootball and feel a few root ends. If the rootball is stiff and dry, soak it in water for a few minutes to soften the tissues. Careful: dried-out roots can snap!

Loosen and untangle roots gently. As you do, trim away black/hollow/soggy roots and remove the old compost trapped between the roots. Refresh the disentangled roots with a thorough rinse to wash away all the tiny bits of soil that can clog up breathing spaces inside the pot.

Settle plant into the new pot. Holding the plant in one hand, place the plant down into the pot. Pour fresh bark mix around the plant, using a dowel or blunt knife to work it all the way down and between the freshly separated roots.

Water thoroughly. Then test your patience: wait a full week or two before watering again—that break stimulates root growth in the new medium.

Know your orchid.

While this basic potting method works for most orchids, some require special care, such as dividing or mounting. Our Lenhardt Library is a great resource for specialty orchid information—we've counted more than 600 books, videos, and other orchid resources there, all available to smart gardeners in one beautiful space! Come in for a visit while you're at the Orchid Show!

Indoor Plant Care
May, May, May, May, May, May

indoor plant Desert RoseBegin to harden off warm-season transplants, moving them into a cold frame or protected area.

Gradually move houseplants outside to protected areas. Large houseplants in plastic pots should be slipped into larger heavier pots to prevent them from falling over in wind. Guard against overexposure to afternoon sun. Carefully monitor for insects during their time spent in the garden.

Overwintered tender annuals or tropicals (e.g., hibiscus, gardenia, geranium) may be pruned, fertilized, and taken outside once night temperatures reach 40 degrees.

Amaryllis bulbs (in their pots) can be moved to a protected spot in the garden where they receive morning sun. Fertilize twice a month with a dilute 15-30-15 mix.