Common yellowthroat (Geothlypis trichas)
The Midwest’s spectacular show of native spring flowers coincides with another extraordinary regional event. As northern birds, like the juncos (p. 207) that spend the winter in the Midwest, depart north for the summer, tiny, gorgeously colored warblers, robins, native sparrows, woodpeckers, and hummingbirds fly in by the millions from winter homes as far away as South America. At the end of their long journeys, the migratory birds begin to reproduce and seek tiny insects and caterpillars to feed their young, as do cardinals, chickadees, and other year-round residents. For birds, the native spring flowers play an essential role: hosting a variety of insect caterpillars and attracting quantities of tiny insects.
Many early spring flowers are ephemeral, so they take advantage of available sunlight before it is blocked by leafed-out plants. This brief window of opportunity attracts pollinators. Frequent visitors include various bee species, some just emerging from their underground wintering quarters. Some bees, such as honeybees and bumblebees, are generalists. Others, like the tiny, solitary bees called oligoleges, are specialists. Codependency requires these insects to pollinate specific species/genera of flowers. If a population of specialist bees fails to locate its special flowers, it cannot survive. The loss of one native bee population puts existing clumps of the beedependent flowers at risk.
Many insects contribute to the spring insect tapestry, but for native plants, none are more important than the ants. Wild ginger, blue cohosh, goldenseal, twinleaf, bloodroot, and trillium are some of the many native woodland spring flowers that depend on ants to distribute their seeds, and not on wind (as do some flowers and most grasses), because trees block the wind. The ants are attracted to the plant seed’s edible fleshy protein-rich appendages, or elaiosomes, which they carry to their nests to eat later. “After the ants have consumed the elaiosomes, they take the seeds to their waste disposal site, and ‘plant’ them in this nutrient rich environment.”7 Ants have been observed carrying wildflower seeds 30 feet away from a plant.8 Like bees, ants are an example of codependence, which benefits both parties and has existed since time immemorial. Wasps and mammals also perform this vital seed dispersing. Introduced nonnative ants may enter into or disrupt these mutualistic interactions between numerous plants and other insects.9
Another force disruptive to the mutualistic interactions between native plants, butterflies, and other insects is spring cleanup. Most homeowners give little thought to this modern-day ritual. We may notice that there seem to be fewer butterflies, fireflies, and birds around, but we rarely connect this circumstance to our gardening practices. Yet, the leaf litter that naturally mulches and fertilizes the soil holds insects in various stages of their lives. Removing these layers and/or covering them with sterilized mulch from the hardware store inhibit the growth of native woodland plants. It deprives robins, native sparrows, and other birds of insect food. It also deprives baby firefly or lightning bug (really beetle) larvae that live in the soil of the worms, snails, and slugs they eat, preventing their development into the adult fireflies that add magic to our summer evenings. Cutting host plants down too early kills the baby butterflies that overwintered as larvae or pupae. Gardeners who leave host plants in place through late spring help overwintering butterflies successfully reproduce. There is also the possibility of observing the emergence of adult butterflies that spent the winter there in their other stages of life. Leaving leaf litter intact enables gardeners to observe the robins, native sparrows, and other spring migrants that search for dormant insects, worms, and other bugs. Natural leaf litter enhances the beauty of woodland wildflowers that grow in soils rich in natural mulch. Choosing native host plants and conducting suitably restrained spring cleanups, including not using pesticides, are easy techniques for gardeners who love butterflies, fireflies, and birds and hope to see them prosper.
American robin (Turdus migratorius)
White-throated sparrow (Zonotrichia albicollis)
The benefits offered by native flowers, such as providing nectar and pollen and serving as butterfly reproduction sites, are rarely equaled by introduced flowers. For gardeners interested in fostering bees, birds, and butterflies by planting native spring flowers to replace introduced (that is, exotic, nonnative) spring flowers, we offer the following suggestions.
Nonnative:
AJUGA, BUGLEWEED. Family: Mint (Lamiaceae). Genus: Ajuga (A. reptans). There are other species and cultivars. Origin: Europe. Height: 6–12 inches. Ornamental Attributes: Bluish flowers late spring and summer. Cultivars may have purple or multicolored leaves. Cultivation: Partial shade. Well-drained soil. Can be a persistent weed. Invasiveness Note: Naturalized or invasive in much of the Midwest.
Ajuga (Ajuga reptans)
Native Alternatives:
GREEK VALERIAN, CREEPING POLEMONIUM, JACOB’S LADDER, SPREADING JACOB’S LADDER. Family: Phlox (Polemoniaceae). Genus: Polemonium (P. reptans). Height: 8–18 inches. Ornamental Attributes: Large light blue or violet bell-shaped flowers 2–3 weeks April to June. Foliage remains green through fall. Cultivation: Sun/shade. Moist or average garden soil. Note: Threatened or endangered in parts of the Midwest. Nature Note: The flowers attract Eastern tiger swallowtails (Papilio glaucus) (p. 136) and spring butterflies, skippers, moths, honeybees, bumblebees, and the ruby-throated hummingbird, the only hummingbird that breeds in eastern North America. Greek valerian is pollinated by a specialist bee: the Andrena polemonii, an oligolege of Polemonium species. Nonnative Note: Don’t confuse Greek valerian with the European Jacob’s ladder, also known as charity (P. caeruleum).
Greek valerian (Polemonium reptans)
Ruby-throated hummingbirds (Archilochus colubris)
Other Native Alternatives:
CANADIAN ANEMONE (see below); CANADIAN WILD GINGER, p. 76; WILD BLUE PHLOX, p. 38; WILD GERANIUM, p. 47.
Nonnative:
ANEMONE, SNOWDROP ANEMONE. Family: Buttercup (Ranunculaceae). Genus: Anemone (A. sylvestris). There are cultivars. Origin: Europe. Height: 10–18 inches. Ornamental Attributes: White flowers. White woolly fruit. Cultivation: Light shade. Moist soil. Very aggressive; WOOD ANEMONE (A. nemorosa). There are cultivars. Height: 6–8 inches. Early spring.
Wood anemone (Anemone nemorosa)
