and were not introduced by direct or indirect human actions. These days it is easy to obtain native flowers, shrubs, trees, and grasses from the many native plant nurseries that sprung up in response to the needs of today’s buying public. In addition to native plant mail-order catalogs, Web-based native plant catalogs, local native plant nurseries, and native plant landscapers there are native plant sales run by park districts, forest preserves, community organizations, and native plant associations. Following each native plant entry we present a nature note, referencing some of the connections between a native plant and wildlife, especially butterflies and other native insects, because most native insects lay their eggs on native plants, which they require for successful reproduction.
Some plants in this book may be familiar under other common or botanical names. We often list several common names for nonnative plants and native alternatives (later references to the plant use only the first common name listed). But a plant’s botanical name is its only positive identification. This is why its botanical name should be verified before making a purchase or before incorporating plants provided by a neighbor or a friend. Occasionally even botanical names change, so if one doesn’t ring a bell, check its current status. For example, due to reclassifications of an American genus, Symphyotrichum is increasingly used instead of Aster. For butterflies, common and taxonomic names have changed significantly, and some quite recently, over the past century.
Our focus on native plants in the Midwest, an admittedly broad and imprecise region, is complicated by the existence of varying definitions, categories, and climate zones. We include Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio, Wisconsin, and Ontario, Canada, in accordance with the Midwest Invasive Plant Network’s (MIPN) view of the region; here gardening practices are similar. However, our suggestions for native plants apply to most states that are adjacent to those set forth above.
USDA Hardiness Zones Maps show ten different zones, each of which represents an area of winter hardiness for the plants in our natural landscape. However, there are many plants that share hardiness zones but are native to entirely different geographical locations and ecosystems. “Hardiness ratings alone are inadequate to guide landscapers in selecting the most successful plants,” states the United States National Arboretum.1 That climate zones are changing is another consideration. For example, the USDA puts Chicago into Zone 5b, with the outlying areas falling into the slightly harsher Zone 5a. The Arbor Day Foundation’s updated hardiness map places the
Chicago lakefront and southern suburbs into the upper reaches of Zone 6.2 Another way of analyzing the region to which a plant is native is by its plant province or regional vegetation type. The Midwest states we reference fall into the Eastern Broadleaf Forest Province or vegetation type.3
You can quickly determine whether a plant is native to North America, and to your state, by accessing USDA Plant Information.4 Enter the plant’s taxonomic name (or an accepted common name), and this will bring up the plant’s profile, with all its synonyms plus additional Web sites if available. A distribution map depicts the plant’s province, or natural distribution, and, if a nonnative plant, where it has become naturalized or invasive.
The Midwest is home to North America’s most dense monarch butterfly population. But these well-known insects are under threat from dwindling habitat and herbicides that kill the butterflies and the milkweed upon which larvae must feed and upon which the adults depend for food. Gardeners and landscapers who want to benefit the greatest number of butterflies should determine which butterflies are local to their area and garden with these butterflies’ “host plants.” Generally, regionally native flowers, trees, shrubs, grasses, and sedges are the host plants on which butterflies lay their eggs and that their caterpillars (or larvae) eat. Host plants also supply nectar and pollen to adult butterflies, bees, and hummingbirds. To determine whether a butterfly occurs in your area, Jeffrey S. Pippen of Duke University’s
Nicholas School of the Environment recommends accessing “Map Search,” at http://www.butterfliesandmoths.org.
Plant heights, bloom periods, and cultivation requirements can vary with a plant’s geographical location and because of differences in light, soil, and other environmental factors. This can give rise to different information from different sources. For the best results, discuss your garden’s specific requirements with the purveyor before you purchase a plant.
For additional information about native plants and their associated wildlife, check with your state and local bird, native plant, and lepidopterist (butterfly/moth) groups. Also access state departments of natural resources and transportation; natural history museums; botanical gardens; native plant, butterfly, and bird books (see bibliography); national groups; federal agencies; and purveyors of native plants (see “Selected Resources” in the bibliography).
ABBREVIATIONS USED
| EFN | extrafloral nectarines |
| fka | formerly known as |
| NABA | North American Butterfly Association |
| NBII | National Biological Information Infrastructure |
| NRCS | National Resource Conservation Service |
| spp. | a group of species |
| syn. | synonym |
| USDA | United States Department of Agriculture |
| U.S. EPA | United States Environmental Protection Agency |
| USFWS | United States Fish and Wildlife Services |
| var. | variety |
THE MIDWESTERN NATIVE GARDEN
INTRODUCTION
Until recently, conventional gardening did not often include growing native flora, but today gardening with regional native plants and wildflowers is gaining popularity. There has been a “continued blurring of the distinction between wildflowers and garden plants.”1 Today’s wealth of books and magazine articles on gardening with plants and wildflowers native to one’s particular geographical region demonstrate that native plant gardening is moving into the mainstream. Another indication of this is the abundance of native plant nurseries, mail-order and online native plant catalogs, and local native plant sales. Even large commercial garden centers are beginning to offer limited selections.
So,
