Even nectar-loving hummingbirds feed insects to their offspring, although goldfinches and doves are an exception; they feed their nestlings regurgitated seeds. Ecologist/ entomologist Douglas W. Tallamy compared native plants and alien plants in terms of their production of caterpillar-stage insects eaten by insectivorous birds. “The native plants in the study supported a whopping 35 times more caterpillar biomass than the aliens.”16 Growing native plants is a meaningful way to encourage healthy populations of native birds and butterflies.
Garden columns offering advice about avoiding mistakes or attracting butterflies and birds sometimes suggest planting your neighbors’ tried and true “old favorites.” But, too often, the result is yet another garden or landscape dominated by nonnative plants, thus aggravating the problem of decreasing populations of native plants, butterflies, and birds. Another by-product of choosing nonnative plants that are often found in ornamental plantings and landscapes is that the nonnatives may be naturalized or invasive. “In fact, many non-native plants introduced for horticultural and agricultural use now pose a serious ecological threat,”17 according to the Bugwood Network. There are economic implications as well: “The economic cost of invasive plants is estimated at more than $34 billion per year, and the costs continue to grow.”18
There are nonnative plants that grew here for decades without becoming invasive, but a federal study determined that “the longer nonnative plants are sold commercially, the greater the chance they will become naturalized and potentially invasive.”19 The rate of naturalization is hard to predict. “Many decades often pass between the first introduction of a plant and its eventual rapid spread. In other words, species that rarely spread today may turn out to be troublesome 40 years or more from now.”20 Dame’s rocket (p. 38) is an instructive example. Many ecologists agree that “a foolproof system for predicting invasiveness has proven elusive.”21 Putting regional native plants into mainstream use in our gardens and landscapes reduces the impact of nonnative invasive plants. The New England Wild Flower Society puts it this way: “By using native plants, we can avoid invasive plant species . . . that harm natural areas.”22 For those who wish to avoid planting a potentially invasive nonnative plant, the Brooklyn Botanic Garden says, “the most prudent prevention measure is to choose a regionally native species.”23
Studies show that “most of the ornamental species in parks and gardens are alien, e.g., lawn grasses, rose bushes, lilacs. Therefore, with as many as . . . one-third of the species in the flora foreign, they dominate the visual impact of the flora in much of middle North America.”24 How did this begin? European settlers in North America felt threatened by the vast wilderness, and they missed their familiar, back-home shrubs, trees, and flowers. Because the native flowers were so plentiful, pioneers called them “common” or “weeds,” unflattering names that persist to this day. To satisfy their customers, colonial nurseries imported European plants, beginning the long-term trend of importing ornamentals. But today’s gardeners have the information, desire, and ability to reverse yesterday’s habits now that a wide selection of beautiful native plants and wildflowers is conveniently available from reliable commercial sources.
We’ve examined a range of well-documented reasons that Midwest gardeners are inspired to choose regionally native plants. Regardless of the motives that resonate with you most, we offer some great native choices within this book. For the best results, go at your own pace. Go beyond our suggestions. Develop your own ideas based on your research and observations. Extend the concept of replacing nonnative plants with natives to include nonnative trees and shrubs, window box plantings, rooftop gardens, and all planters. Share native plants with your friends and neighbors. Collect native-plant nursery catalogs and spend time dreaming about beautiful native plants and flowers, rather than the nonnative varieties. For landscapes and gardens large and small, our book can serve as a handy guide for choosing native midwestern flowers and plants.
Environmental Reminder
Removing native plants from their natural environments increases their vulnerability. Removal also decreases survival chances for the beneficial insects, including butterflies, skippers, and bees, that depend on native plants for survival. Patronizing native purveyors (see “Selected Resources” in the bibliography) and sharing native plant bounty among friends, relatives, and neighbors are responsible ways to acquire native plants.
1
SPRING
“The winter wind has lost much of its cutting edge,” wrote naturalist John Madson about the midwestern spring. “From then until hard frost, there will be no time when the prairiescape is not enameled with flowers of some kind. From the first pasqueflowers of March to the towering sunflowers of October, the tallgrass prairie will never be without flowers.”1 March brings the first pasqueflowers, but for another twentieth-century nature lover, Patricia Duncan, “the month of May is the apex of the spring prairie. Green is taking over, bird song is taking over, and insects are taking over. Wildflowers such as golden alexanders, birdsfoot violets, prairie rose, spiderwort, purple milkweed . . . are taking over.”2 Midwestern spring flowers had nineteenth-century admirers, too. “The earth in the woods is covered with May-apples not yet ripe, and in the enclosed prairies with large fine strawberries, now in their perfection.” Also beautiful are “the red lily, and the painted cup, a large scarlet flower,”3 wrote William Cullen Bryant. Visiting Illinois to be with her sister, Eliza W. Farnham wrote, “The landscape grows more beautiful every day. The prairie puts on its richest garb about the first of June. The painted cup, moccasin flower, and geranium, come out.”4 Observing spring while touring the Great Lakes in 1843, Sarah Margaret Fuller wrote, “In the wood grew not only the flowers I had before seen, and wealth of tall wild roses, but the splendid blue spiderwort, that ornament of our gardens,” and the “most delicate flowers,” including “a familiar love, the Scottish harebell, the gentlest, and most touching form of the flower-world.”5
After our long winters, midwesterners look forward to beautiful spring flowers. It’s too bad that many commercial garden centers, catalogs, and public displays of spring flowers feature ornamental plants from Europe and elsewhere. Native spring flowers are just as beautiful, and their nectar attracts bees and butterflies. Midwestern wildflowers also play an essential role in butterfly reproduction, because these insects lay their eggs only on host plants that the caterpillars, or larvae, can digest, which most often are native plants. Several fritillary butterfly species lay their eggs on or near native violets, sometimes when the host plant has already dried up. The parsnip, or black swallowtail, butterfly (Papilo polyxenes) and the Missouri or Ozark woodland swallowtail butterfly (P. joanae) lay their eggs on plants of the Carrot family, such as spring’s golden alexanders (Zizia spp.). America’s best-known butterfly, the milkweed or monarch butterfly (Danaus plexippus), lays her eggs on milkweeds (Asclepias spp.); the spring bloomers among them include blunt-leaved, green comet, and purple milkweed. As is typical of more than 90 percent of insects, most butterflies are restricted in their diets to native plants, because they “have not developed the enzymes” required to digest the leaves of nonnative plants.6
American redstart (Setophaga ruticilla)
Yellow warbler (Dendroica petechia)
