You can bring a taste of the forest to your garden by planting a few of the wildflowers that bloom in spring in our native woods.
Many woodland plants flower in early spring to take advantage of the sunshine that reaches the forest floor before trees open their leaves. “They’ve evolved to seize that opportunity,” said Spencer Campbell, Plant Clinic manager at The Morton Arboretum in Lisle. These wildflowers are known as spring ephemerals, he said, because “you only see them for a short time in spring before they go dormant and disappear for the rest of the year.”
Sharp-lobed hepatica, with white, light blue or pale purple blooms, and bloodroot, with white flowers, are usually the first to bloom in the Arboretum’s East Woods and other wooded areas in late March or early April, depending on the weather. They are followed by tiny sparkly pink spring beauty, jaunty Dutchman’s breeches, blue Virginia bluebells, yellow bellwort, stately white great trillium and many more. Their blooms provide nectar and pollen for bees, wasps and other insects early in the spring.
By mid-May, when the trees’ canopy of leaves has closed in overhead, most are done. Wild geranium and wild blue phlox are usually among the last to bloom in the now-shady woods.
Among the wildflowers that can do well in shady gardens, with proper soil and care, are bloodroot (Sanguinaria canadensis); Virginia bluebells (Mertensia virginica), which sport purple buds that open to bluebell-like blooms in early May; bellwort (Uvularia grandiflora), aptly named for its yellow dangling bells; Jack-in-the-pulpit (Arisaema triphyllum), with a distinctive hooded flower; wild blue phlox (Phlox divaricata), with clusters of small flowers the color of the sky; and wild geranium (Geranium maculatum), with pale purple blooms.
If you’d like to try a few of these plants, make sure any wildflowers you buy have been grown for gardeners and not taken from the wild.
“Never dig them up from natural areas,” Campbell said. “They’re a critical part of the native ecosystem that includes the wildlife and the trees.” Instead, buy them from native plant sales or from reputable growers that do not take plants from the wild. Since most woodland wildflowers are difficult to raise from seed, it’s best to buy them as plants. If they do well, they may reseed after several years.
Woodland wildflowers can be particular and they won’t thrive everywhere. They will need a site that is in part shade or shade, with well-drained soil that is rich in organic matter. “The soil in the woods has been built up from decaying layers of leaves for thousands of years,” he said. “It has a much lighter texture and more organic matter than our typical garden soil.”
Prepare the planting site in your garden by digging lots of dry leaves into the soil. Plan to leave autumn leaves in place every year over any area where you have planted native plants, so they will continue to enrich the soil.
One of the best places to plant spring wildflowers is around trees. “That’s their native habitat,” Campbell said. Under the layer of mulch that you spread to protect your trees’ roots, the wildflowers will be undisturbed during their long dormant period in summer, fall and winter.
Be careful not to damage tree roots when planting around a mature tree. “The safest time to establish any companion plants for a tree is actually when you plant the tree before it has spread out roots that can be damaged by planting nearby,” he said. If you must plant around an established tree, dig as little as you can.
Keep the soil moist until the wildflowers are well established, but skip the fertilizer. These plants prefer to get their nutrients from the decay of organic matter in the soil.
“They do best if they’re planted in the right place and then left alone as much as possible,” Campbell said. “Plant them in an appropriate spot, and then wait for spring to see if they pop back up.”
For tree and plant advice, contact the Plant Clinic at The Morton Arboretum (630-719-2424, mortonarb.org/plant-clinic, or plantclinic@mortonarb.org). Beth Botts is a staff writer at the Arboretum.
