I love this time of year. Each time I go outside and walk through my garden, I find another wildflower in bloom. Many of these spring wildflowers are ephemerals, meaning that they foliate, bloom, and then go dormant; thus they work well in shady gardens. They glory in the sunlight they receive before the trees leaf out but the challenge, of course, is having something planted nearby to fill the space that will be left bare.
Some candidates that come immediately to mind are Vinca major (Periwinkle), Viola odorata (Violets), Primula vulgaris (Primrose), Asarum splendens (Ginger), and Lamium maculatum (Dead Nettle).
Dicentra cucullaria (Dutchman’s Breeches), hardy in zones 3-7, is intolerant of wet winters; therefore, good drainage is crucial. Somewhat similar in appearance to Dicentra eximia with its blue-green, fern-like foliage, the white, yellow-tipped flowers resemble fat, inverted pantaloons that are stacked in spaced layers up the six to twelve inch stem that arches above the foliage in early spring. This Dicentra will grow in full shade as well as partial shade and will disappear from the garden by early summer.
Mertensia virginica (Virginia Bluebells), hardy to zone 3 has large, ovate leaves and sprays of true blue flowers on eight inch stems in April and May. By June or July at the latest, this plant has completely disappeared. I suggest interplanting ferns that push up their fronds while Mertensia is in bloom and then proceed to uncurl and spread out while Mertensia goes dormant.
Blooming at nearly the same time is Sanguinaria canadensis (Bloodroot). Hardy to zone 3, the buds of these white flowers appear in the furl of the scalloped, round leaves. As the flower blooms, the leaf unfurls. The short foliage remains longer than that of other ephemerals, finally disappearing in midsummer.
Anemone nemerosa (Wood Anemone), hardy in zones 4-8, looks a bit like a more delicate hardy geranium with its deeply-toothed, divided leaves. The late April/early May-blooming, open flowers vary in color, depending on cultivar, from white to shades of blue or pink and are held well above the foliage on six to eight inch stems. This Anemone spreads by rhizome as well as seed and will thrive in deep shade as well as partial shade.
Another delicate wildflower, hardy to zone 4, is Anemonella thalictroides (True Anemone). The foliage of this plant is slightly lobed like that of Thalictrum. An umbel of tiny white, multi-petaled flowers waves on a six to twelve inch stem a few inches above the foliage. Anemonella thalictroides begins blooming in May and continues well into June with sufficient moisture. It also goes dormant thereafter so I suggest interplanting it with a dwarf Platycodon (Balloon Flower) or Ceratostigma plumbaginoides (Plumbago, zone 5) which usually don’t foliate until the beginning of May.
Most of the spring wildflowers are delicate in appearance so plan to site them where they will easily be seen. Purchase them from a nursery that propagates them responsibly, i.e. does not dig them from the wild. The Holden Arboretum, at its yearly plant sale (this year May 3-5), sells a wide array of local wildflowers. All have been propagated at the arboretum. Perhaps you should patronize them. Then you can know that you did the right thing andand will enjoy these tiny pleasures even more.