MIDWESTERN NATIVE SHRUBS AND TREES
INTRODUCTION
THIS BOOK ABOUT shrubs and trees is a companion to The Midwestern Native Garden: Native Alternatives to Nonnative Flowers and Plants, An Illustrated Guide. Its purpose is to serve as a useful resource for homeowners, gardeners, and landscapers seeking to evaluate prospective woody plantings. The book covers the plant qualities that the typical gardener wants to know, such as height, color, and bloom time of the nonnative plants, and their native alternatives. To incorporate a deeper level, it explores profound connections between native midwestern woody plants and the region’s ecological community. The lives of butterflies, bees, and birds are central to the discussion. The goal is to choose the trees and shrubs that make the best use of available space. The multiple objectives of visual beauty, adaptation to the local climate and soil, and maximum contribution to native wildlife can be best achieved by choosing native species for our gardens and landscapes.
Professional landscape designers call trees and shrubs the bones of the garden. “Trees are the most permanent elements in any planting plan,” notes the American Horticultural Society. “Since a tree is probably the most expensive of garden plants and usually the most prominent, selection and siting are the most important decisions. Shrubs can form the backbone of your garden design, and with their variety of foliage, flowers, fruits, and stems, they also provide interest through the seasons.”1 The natives tend to be hardier, longer-lived, and easier to maintain and grow than introductions from faraway places. When it comes to aesthetics, the native trees and shrubs growing in a midwestern backyard, garden, or landscape, regardless of their size, produce four seasons of beauty and visual impact. Midwesterners desiring an aesthetically pleasing, ever-changing tapestry of hardy plants will choose native species instead of the usual nonnative fare offered at most nurseries.
Midwestern Lepidoptera (butterflies, moths), birds, and bees evolved with midwestern plants. They need each other to complete their life cycles. Each native tree and shrub in the backyard is a life-giving force. The huge benefits to wildlife in terms of reproduction, food, and habitat that each native plant provides cannot be duplicated by nonnative species. “Planting nonnative plants, like butterfly bush, in your yard is actually making it harder for the butterflies and birds in your neighborhood to survive.”2 Though it isn’t well known, “more than 90 percent” of our native butterflies and moths can feed only on particular native host plants during their larval caterpillar stage.3 “A butterfly’s most important relationship is with the plants eaten by its caterpillars.”4 Perpetuation of a butterfly species requires a habitat that will support the full life cycle of the butterfly, not just the adult stage.5 Importantly, many native trees and shrubs excel as host plants that benefit butterfly and moth populations as well as the birds that eat the caterpillars and feed them to their offspring.
Gardeners and landscapers can choose plants on the basis of their roles in the local ecosystem. Nonnative shrubs and trees occupy spaces in our yards, gardens, and landscapes that would be better filled by native woody species that increase biodiversity. The online USDA PLANTS Database enables us to access individual plant species, determine if they are native or introduced, and check the maps. Plants shown as introduced (“I”) are defined as naturalized, not native to the area, and, in general, “likely to invade or become noxious since they lack co-evolved competitors and natural enemies to control their populations.”6 Plants shown as native (“N”) can be checked for their distribution in the United States and Canada, classification, synonyms, legal status, data sources and documentation, and related links. Reliable information takes the uncertainty out of shopping. When we choose midwestern native plants, we attract birds, butterflies, and other wildlife that add an additional layer of beauty to our yards and gardens.
Whether used as a sanctuary, a miniature nature preserve, or a playground for children, yards, landscapes, and gardens of native plants are a sound investment and provide peace of mind. Midwestern native plants have been here since the last Ice Age. For more than 10,000 years, these plants adapted to the region’s soils, seasons, rainfall, and wildlife. Native woody and herbaceous plants are beautiful and hardy, and once established they require less maintenance than conventional lawns and nonnative ornamentals. Because native plants have adapted to local conditions, they are more resistant to pest problems. Synthetic pesticides, herbicides, and fertilizers have no place in the native garden, as they kill butterflies, other pollinators, and the plants themselves and harm human health. (If problems arise, we can employ other ways to control them.) Natives rarely need watering. They improve water quality and reduce flooding, serve as carbon sinks, and reduce the demand for nonrenewable resources. The US Environmental Protection Agency (EPA) explains that “native landscaping practices can help improve air quality on a local, regional and global level. Locally, smog (ground level ozone) and air toxics can be drastically reduced by the virtual elimination of the need for lawn maintenance equipment (lawn mowers, weed edgers, leaf blowers, etc.) which is fueled by gasoline, electricity or batteries. All of these fuel types are associated with the emissions of [many] air pollutants.”7 Reduced lawn and expanded native plantings produce healthier environments, and the absence of loud machinery brings peace and quiet. Regionally native plants create an authentic sense of place in the landscaping at home, in parks, and in other public places throughout our communities. While creating a future for the regional ecosystem, native gardens with diverse plants that attract a host of birds, butterflies, and beneficial insects also serve as convenient places to learn about plants and wildlife and simply enjoy nature.
There are other benefits. Gardens of native plants reduce opportunities for nonnative plants to overrun the landscape. Seed from native plants that is carried by wind and birds from our garden into natural areas does not degrade the environment. “Nonnative plant species pose a significant threat to the natural ecosystems of the United States. Many of these invasive plants are escapees from gardens and landscapes where they were originally planted. Purchased at local nurseries, wholesale suppliers and elsewhere, these plants have the potential of taking over large areas, affecting native plants and animals and negatively changing the ecosystem.”8
The statistics are alarming. In the United States, more than 100 million acres of land have been taken over by invasive plants and the annual increase has been estimated to be 14 percent.9 “The impact of all of these nonnative plants is creating novel ecosystems that are not supporting food webs, therefore not supporting biodiversity.”10 The huge numbers of nonnative