A senior horticulturist shares his colorful secrets
A sure sign of spring every year: when the 64 handmade troughs arrive at the Heritage Garden, filled with the first flowers of the season.
Smart gardeners are always on the lookout for great container plans, and this year’s trough design, masterminded by senior horticulturist Tom Soulsby, is a sunny, happy mix that would work for many a porch pot or deck display. Why did he choose these particular plants? Soulsby was happy to share tips on plant selection and working within a container’s constraints.
Tip #1: Work with the proportions of the space.
In the low-to-the-ground containers, no plant is taller than 12 inches, and most are in the 3- to 6-inch range. Keep heights low, but allow for a range—from creeping near the ground to a foot in height.
Tip #2: Scale matters.
Flowers are intentionally small in this mix, with tulips as the largest in the bunch. Diminutive flowers—nemesia, bacopa—get their moment in the sun, and don’t disappear when they’re in the company of other smaller-scale companions.
Tip #3: Mix it up.
The riotous mix of mats, spikes, lettucey leaves, and textures is what gives the container its charm. Soulsby used 15 different kinds of dwarf, short, and smaller-sized flowers in each container, planting two or three of each to help knit the mix together.
Tip #4: Break the rules.
Yes, you could plant in clusters of threes, place the trailing plants in the corners, and put the tallest plant in the center, but the wilder, looser style of random planting suits this kind of planter better.
Short and shaggy, Narcissus 'Rip Van Winkle' grabs attention with its bright color and "bad hair day" charm. It's an old-fashioned variety dating to 1884. After the planter has finished its six-week course, dig out the daffodil bulbs, store them in a cool spot, then replant them in your yard this fall.
Tulipa kaufmanniana 'Chopin', like many in its species, is known for its decoratively patterned foliage, as attractive before bloom as after. Tom plants just one bulb per container, since its "larger" flower dominates the mix as it blooms.
Small but mighty, Tulipa whittallii, a species tulip, makes a big statement with pointy petals and fiery, red-orange color. As with daffodils, dig up tulip bulbs post-planter and site them in your yard come fall. (If the leaves are still green, you can plant the bulbs right away after removing them from the spring containers.)
Also known as toadflax, linaria likes early spring's cool weather, fading fast once the weather turns warm. Linaria maroccana 'Fantasy Yellow' might get lost in a large bed, but its dwarf size and delicate-yet-heavy bloom work well in this container.
Dense with tiny flowers, this sutera, also known as Bacopa Big Falls™ White (Sutera grandiflora), acts like a ground cover, trailing and spilling over container edges (it's a great choice for baskets, too).
Creeping plants like sedum lay low, tumbling over container edges and winding through the stalks and stems of other plants. Use Sedum rupestre 'Angelina' in mixed containers when it's small, then transplant it into garden beds, where it will keep growing in size through the season. Great bright lime color and crisp texture.
Popular even in Shakespearean England, primroses are perennials that can work in a container, too. Valuable for rich, bright colors, varieties like Primula vulgaris 'Primlet Golden Shade' also add lots of texture, with ruffly flowers and crinkled leaves.
One of the last to bloom in the bunch, bluebells (this variety is Hyacinthoides hispanica 'Excelsior') ring in spring and provide the visual punch of taller, 10- to 12-inch flower spikes topped by dangling, deep blue bells.
Baby Blue Eyes
A welcome spot of beautiful blue color in spring, Nemophila menziesii fills in the gaps once the earlier-blooming linaria has eased off on flower production. Lettucey foliage adds texture as the plant grows—post-container, replant it to reach its true big, billowy size.
In a low planter, a little trailing goes a long way. Namid Early Yellow bidens (Bidens ferulifolia) spills and trails just enough to look outstanding, not out of control.
False Sea Thrift
The "tallest" plant here, at 12 inches high, false sea thrift (Armeria pseudarmeria) bobs above the crowd on wandlike stems, adding an airy and rather delightful touch.
Why include simple violas? For their wonderful scent, expecially lovely in the morning. A six-cell pack of violas lets you fill in the inevitable bare spots between other plants or along edges. While this variety has an unmemorable formal name (Viola cornuta), you can look for Denim Jump Up violas at your local nursery.
Dwarf size and early blooms make smaller nemesias naturals for spring planters. Tom chose Nemesia foetans 'Poetry Pink' for its particularly dense and bushy habit and riveting color combo.
Coral color and dark leaves work wonders in a container. Dianthus deltoides 'Shrimp' is a 6- to 8-inch variety that Tom suggests for rock gardens, too.
Keep twinspur (Diascia barberae 'Juliet Light Pink') well watered, and it will reward you with plentiful blooms. When summer comes, shear it back by 50 percent, and it will start the process—and reward you—all over again.
And one final, smart, gardening tip from Tom Soulsby: regular potting soil works fine in a container like this, but do fertilize every ten days or so with a basic 10-10-10 application, to keep this wonderful mix of plants blooming beautifully.
Karen Zaworski is a garden writer and photographer who lives and gardens in Oak Park, Illinois.