Prairie restoration is the process by which we attempt to restore the native plant matrix of the prairie in areas where prairie formerly existed. At the time of settlement (prior to 1840), prairies dominated areas of southern Wisconsin and grew more abundant further south and west into Illinois and Iowa. Today, there are several towns, such as Sun Prairie and Prairie du Sac named for the prairies that the settlers first encountered. These areas were extensive, rich, and diverse grasslands encompassing thousands of acres. The plant and animal diversity of the prairie was incredible. Often, remnant prairies are found to have upwards of 300 species per acre. Thousands of species of birds, animals, and insects evolved to live and thrive in the prairie ecosystem.
Sadly, few healthy remnants of the original prairie exist today and most are quite small. To get a sense of the character and scope of the prairies that the first settlers in the region encountered, you can go to several preserves in the region including Nachusa Grasslands south of Byron, Illinois, and Chiwaukee Prairie near Kenosha, Wisconsin.
However, small remnants do exist in many places and if you own a few acres you may indeed have a small remnant located along a fence line or roadside or possibly in some other inaccessible or un-plowable piece like an old farm dump or quarry. It may be covered in trash or choked with brush or invasive species. You may be surprised just how resilient these little areas can be. It is not unheard of to find rare plants clinging to life, just waiting for their chance.
The process of restoring a prairie can be complex depending on the condition of the site to be restored. The biggest hindrance to success is the presence of weed seed in the soil. Weeds germinate quickly and even if they are annual weeds, they can greatly hinder the growth of prairie seedlings. Rich, weedy soils are the hardest to deal with. Surprisingly, soils that are sandy and “poor” in terms of their potential for crop production are often the easiest to deal with.
A prairie restoration begins with proper site preparation to minimize these threats.
Prairie species employ a variety of tactics to grow and thrive. Many require a period of cold and wet conditions (called stratification) before they germinate. Other seeds must pass through the gizzard of a bird or the gut of an animal. Generally, this can be simulated and seed producers understand this process.
In addition, it is possible to buy prairie seeds on the internet that may have come from other regions and even other continents. It is critical to know the origin of seeds and plants used in restoration.
Depending on the circumstances, seeding may be done by hand, with a mechanical broadcaster or using a specialized seed drill. Because prairie seeds come in all shapes, sizes and densities it is challenging to get it spread evenly. Seeding in spring (prior to June 15) or fall after November 1) is best. Different species will be favored or disfavored, but even more important is the weather. A drought year can really reduce the success of a prairie planting.
After seeding, the prairie should be mowed at a height of about 12 inches several times the first year and possibly the second. This denies weeds the opportunity to produce seed and allows light to get to the tiny prairie seedlings. Don't be surprised if you can't find the prairie plants. They are very inconspicuous. An expert can probably identify some of them, but in fact some species may not germinate for several years. By the third growing season your patience should start to pay off and you should be ready for a prescribed burn.
Burning every year for the first several years will help prairie plants compete against the weeds, but once well established, the site should be broken into 3-5 areas or units, one of which should be burned each year. This keeps the habitat in place for some birds and allows beneficial insects to complete their life cycles. By the time you hit year five, your prairie should be looking fine. But don't lose interest! It will keep changing year after year as new plants emerge and new creatures recolonize the land.