Why native plants are better for your backyard -- and the prairie
Picture a field of tall Queen Anne's lace bending in the summer breeze. Honeybees are buzzing around sweet clover at the edge of the field, and small cabbage white butterflies dance over yellow mustard flowers. Ah, the Illinois prairie! Well, not quite.
While lovely, the field just described is dominated by nonnative plants and animals. Queen Anne's lace, sweet clover, and cabbage white butterflies are from Eurasia. The yellow mustard originated in Asia Minor. Honeybees hail from Europe. You can find them in "wild" areas all over Illinois. So, what does it mean to be "native?" What is "nonnative?" How do you tell the difference?
A native plant is one that lived and reproduced here before European settlement. Native species (sometimes called endemic) can refer to a plant, an animal, a fungus or any living thing.
In Illinois, the reference point is roughly the year 1800. In other areas -- indeed, on other continents -- the point of reference may be different. It's generally the time before the abrupt changes in industrial and technological development.
On the flip side, a nonnative species is one that lives here now but did not live here before European settlement. Nonnative species travel through humans. Sometimes they're brought intentionally, like the European starling, imported to the United States by well-meaning Shakespeare fans who wanted representatives of every bird mentioned in his works.
Others hitched a ride. The zebra mussel is a classic example of an accidental introduction. Native to waters in Central Asia, this small mussel was taken up in ships' ballast, traveled across the seas, and deposited in the Great Lakes when the ballast was discharged.
Once in a new habitat, a nonnative species may or may not be able to reproduce independently. We generally like the ones that stay put, especially in our gardens.
Potted geraniums are a good example. If we want more potted geraniums (which are African in origin), we have to propagate them in greenhouses. Other nonnative species, though, can reproduce in their new habitat. And, boy, do they!
Fecund nonnative species reproduce with abandon, spreading to every available nook and cranny in their new home. That's when there's trouble.
An invasive species is a nonnative species that reproduces and spreads like crazy. This group comprises plants, fungi, birds, mammals, reptiles, fish, amphibians, and all kinds of invertebrate creatures. Invasive species do tremendous damage to native ecosystems and man-made environments as well.
One of many examples of the havoc wreaked by invasives is the notorious vine, kudzu. Power companies spend millions of dollars annually to remove kudzu from power lines.
There's no quick-and-easy way to tell the difference between native and nonnative species. Ecologists know which plants and animals are native by studying the journals of European explorers, 19th-century surveyor's notes, plat maps, and the journals of settlers. As for nonnative species, there are records of many of the introductions.
The Illinois of the 18th century would look very different from the Illinois of today. There were no fields of Queen Anne's lace and sweet clover. Floyd Swink and Gerould Wilhem wrote in their 1994 tome, "Plants of the Chicago Region," "more than one-third" of the plants we see today, "were not here prior to European settlement." Weeds, they wrote, "dominate more than 95 percent of the vegetated landscape."
Why be concerned about what's native and what's not? Our natural heritage is slipping away, and our health and well-being rely on a healthy, diverse environment. The concept of native and nonnative species is fundamental in healing the wounds of the past 200 years. Allowing and encouraging native species to live in their native habitat is part of the healing process.
You can get to know natives by introducing them to your garden. You don't have to go full-out with natural landscaping (although that's awesome to do). Just a few native plants in your garden can attract native bees and aid in pollination overall. Native birds like native plants, as well.
Dig in a little, get to know your native plant neighbors, and watch the wildlife they attract. For native species, this is home sweet home.
• Valerie Blaine is a naturalist and native plant enthusiast. You may reach her at email@example.com.