To eliminate some of the confusion out there, especially since native plants are becoming more popular, I thought I’d explain What is a native plant?
The textbook definition of native plants is they are the plants that have been growing in area prior to European settlement. Another way to define native plants is : Native plants evolved or adapted to our local environment for thousands of years, and are an important part of our local habitats, ecosystems and ecosystem services (pollination, infiltration, carbon sequestration, etc). They are the most sustainable plants for our specific area. Our native plants not only adapted physically, but chemically and genetically.
Our Illinois prairie plants adapted to our local environment by developing deep root systems which allow the plants to absorb large amounts of water during heavy rainfalls or snow melts, and to find water from deep underground during droughts. These deep root systems improve our soils by continuously add organic matter deep down (more than >10 feet). This not only benefits the plants themselves, but improves infiltration, increases carbon sequestration, and benefits many organisms. Although our woodland plant’s root systems are not as deep as the prairie plants, our native woodland plants also increase infiltration, improve soil quality, provide wildlife habitat, and provide many other ecosystem services. The same holds true for native plants found in our savanna and wetland habitats. Just take a look at a mature bur oak tree and you’ll know the extensive root system, trunk, branches, and leaves, all provide these benefits.
By adapting to wildlife and other ecosystem components, native plants both benefit and depend on them. For example, wildlife, soil orgnisms, rock minerals and water all help native plants with photsynthesis, pollination, seed dispersal, soil aeration, etc. In turn, native plants provide wildlife with food, shelter or cover, nesting material, and nesting sites. They also help in the formation of soils from rocks, and help our waters through infiltration and evapotranspiration.
Many people ask me whether cultivars of natives are considered native plants and the answer in general is "no" for these reasons. Native cultivars are usually plants that have taken from the wild and altered by humans for some specific attribute – typically a specific flower or leaf color, shorter height, flower shape, etc. Sometimes when we breed for a certain characteristic, like a larger flower or variegated leaf, we may unintentionally lose or decrease the characteristics that attract wildlife. Genetic diversity is important to a native plant’s ability to adapt and many cultivars are cloned, making them less genetically diverse. Also, when we purchase a cultivar, we typically don’t know whether the plants they were bred from were adapted to our area or another area. For example: a coneflower from northern Illinois is not the same as a coneflower from Nebraska, since their local environments and conditions are different . Another thing to keep in mind especially if you live near a natural area: some cultivars inter-breed with our true native species, and could weaken or change the native gene pool.
Hopefully this clears up some of the confusion. We will be introducing articles about gardening with natives in the future. Denise Sandoval [email protected]