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Why Plant Natives?

Mar 18, 2019

Among the gardeners and landscapers who are about to begin the work of beautifying their yards and communities this Spring, there are many who are dedicated to using native plants in their projects. You may have heard people talking about their preference for natives, and wondered what it is all about. Once you discover their many benefits, you too may be planting them this Spring! 

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(For a printable PDF of this article click here->Why Native Plants)

Those of us who are focused on native plants have much to appreciate in a Midwestern growing season, whether it is mayapple flowers, bursting their buds below their leafy umbrellas in the spring, or Silphiums standing tall over the prairie in late summer. Those who tend a garden full of tulips and daffodils, may wonder about our obsession with these native plants, so I wanted to provide a brief overview of what native plants (and native plant people) are all about.

What do we mean by native?

In any given area a species is considered native to that area if it existed there before humans began moving plants around the world.  If you live in Indiana and have daffodils in your yard, they are not native. That species originated in northern Africa or southern Europe. They would be considered native to that region. They became popular in European gardens, and were eventually imported to and cultivated in the United States. Black-eyed Susan (Rudbeckia hirta), on the other hand, has been growing in the Midwest since long before Europeans arrived on this continent. It is native to Indiana. rud hir

It should be noted that precise definitions of natives can be a bit tricky. Perhaps some plants that are considered native did come from far away, but arrived so long ago that we have no record of their arrival and consider them to be native.  Also, some native plants have been cultivated to produce plants with some new characteristic that a person might find more appealing for their garden. You might find Black-eyed Susans that have been bred to have larger flower heads and additional colors on the petals. These plants are often avoided in native landscape restoration projects because they lack genetic diversity, which may make them them less fit to survive in the habitat and less valuable to wildlife .

Why do some people focus on native plants?
If you have ever seen the deep red spikes of Cardinal flower shooting up like 4th of July fireworks from the edge of a wetland, or walked through a field ablaze with the burning orange of butterfly weed, then you may have all the reason you need to appreciate native plants. Aside from their beauty though, there are other important reasons to use native plants in a landscape. Ask a native plant lover why they are using natives in their landscape and they will likely tell you about the ecological benefits.

Ecological Benefits
To understand these benefits it is necessary to understand how native plants affect biodiversity. Biodiversity refers to the variety of living things in a given area. A half acre of lawn covered completely with Kentucky bluegrass has less plant biodiversity than the same sized area planted with 20 different species of grasses and flowers.

The area planted with 20 different species would not only have more kinds of plants, it would likely attract more kinds of butterflies, bees, and other insects. Many insects are picky eaters. The more options you make available for those picky eaters, the better chance they will arrive at your plant buffet. This wider variety of plants and insects means a wider variety of food choices for birds as well.  It is easy to understand that having more kinds of plants would lead to more kinds of animals, but does it matter whether the plants are native? Yes. Research shows that native plants support more insects and more birds than non-native plants.

Why? It all has to do with matching up the plants with the wildlife that already exists in a region. Insects and other animals have developed important relationships with certain plants. You have probably heard about the important relationship between the monarch butterfly and the milkweed plant. Monarchs would not survive if there were no milkweed plants. By planting a native plant, like common milkweed, you are growing a source of food and shelter for insects that are here and that are adapted to that kind of food and shelter. If you planted a non-native plant, there are fewer insects to benefit from it because most of the insects that depend on it are in another country.

This ecological benefit is one of the main reasons that so many people are focused on selecting native plants. Like other gardeners and landscapers we want to see a variety of beautiful plants, but we also want to maximize the value that our landscape has for wildlife.

As a further benefit, planting natives not only increases the biodiversity in your landscape, it may also help protect biodiversity on a larger scale. As native plants in wetlands, forests, prairies and other habitats have been lost to development, agriculture and non-native lawns, the importance of native landscapes has become more important. Even a small native planting may serve as an important bridge between two disconnected habitats, perhaps allowing butterflies or hummingbirds shelter and food as they move from one habitat in search of another.

In addition to these ecological benefits, native plants have other advantages. Plants that are native to your region are adapted to the region’s soil, hydrology and climate, which means they will typically require less maintenance than plants that are from another region. In the Midwest, many native plants also have deep and extensive root systems, which help stabilize the soil and help create conditions favorable to building fertile soils. They absorb excess nutrients from run-off and enhance water infiltration during periods of heavy rain.

Does this mean non-native plants are bad?
While they may not have as much ecological value, there are many beautiful non-native plants that can help wildlife and can be a pleasant addition to your landscape. Unfortunately, there are also many non-native plants that become big problems when they are brought into a new area. In its native country a plant usually has some limiting factor that keeps it from spreading out of control; a wide selection of insects may feed on it, or it may have to struggle to compete against other plants that are also adapted to its habitat. Once the plant is brought to a new region without those insects or competition, it may grow prolifically and soon dominate a landscape. Sometimes these plants are introduced to a new area accidentally. Sometimes they are planted on purpose by people who did not know the impact that the planting would have.

Across the country, natural resource managers who are trying to preserve natural habitats face the enormous challenge of fighting against aggressive non-native species. These species, also called invasive species, exotic invasives, or alien invasives, can dominate landscapes and crowd out the species that are native to the area.  Garlic mustard, an invasive species brought to the US from Europe in the late 19th century, now threatens biodiversity in forests throughout the eastern half of the United States. In many forests, once filled with trillium, spring beauties, wild geraniums, Dutchman’s breeches and other native wildflowers, invasive garlic mustard has taken over. It is just one of many invasive species causing problems. In the Midwest alone, people working to protect natural areas may be fighting purple loosestrife, phragmites, reed canary grass, autumn olive, Japanese knotweed, glossy buckthorn and many others. These plants have become an expensive threat to the ecological health of the land. Avoiding such ecological risks is yet another benefit of choosing native plants. 

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This doesn’t mean that you cannot incorporate non-native plants into your landscape, but it does mean that you should exercise caution when selecting plants. For many people there is a thrill in being the first to have some new and interesting plant in their landscape. If the plant is not native it may be difficult to determine if that new plant is a threat to become invasive. If you are planting non-native species, it is best to work with plants that have a proven history of sharing rather than dominating the landscape in your region. Unfortunately, there are still nurseries and garden centers that sell plants that are known to be invasive. Some states have passed laws prohibiting the sale of certain listed invasive species, but it is still best to do your own research when shopping at a nursery or garden center that sells non-native plants. Look for information about how quickly they spread and grow. If there are reports of them spreading too quickly, look for an alternative. Or, better yet, purchase from a place that only sells native plants.

Each gardener brings to their landscape their own interests, goals and subjective appreciation of different plants. In addition to their appreciation of attractive plants, native plant gardeners usually bring an interest in wildlife, biodiversity, and ecological conservation. For those who are new to native plants there are many resources to help you get you started. Find a nursery that specializes in your region’s native plants, such as Cardno Native Plant Nursery, for recommendations on plants for your area. State or regional groups like the Indiana Native Plant Society have great resources, including supportive Facebook groups. Local parks and nature centers offer hikes and other programs that can introduce you to the native plants in your area.

With all of these resources available it will be easy to make this the year you enhance your landscape with the beauty and ecological benefits of native plants.
                                                                                                                                 
                                                                                                     - Vince Gresham
                                                                                                                    3.18.19


Resources:
Native Plant Nursery-
www.cardnonativeplantnursery.com
Article: Insect diversity decreases in gardens with non-native plants
https://www.sciencedaily.com/releases/2015/09/150928155900.htm
Benefits of Natives for Birds
https://www.audubon.org/news/new-research-further-proves-native-plants-offer-more-bugs-birds
https://www.audubon.org/news/why-native-plants-are-better-birds-and-people

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