Planted Prairies at Pleasant Valley Conservancy

 

Access a Prairie

 

 

Planted Prairies: Overview

Most of the land at Pleasant Valley Conservancy was remnant or degraded remnant of prairie or savanna. But when restoration began we had about 15 acres of land in 5 relatively small fields that had formerly been used for agriculture. These fields were probably originally prairie, and seemed like good candidates to restore to that state. Click here for details on these planted prairies.

Conservation Reserve Program. The Conservation Reserve Program (CRP) is a voluntary program of the U.S. Department of Agriculture to encourage owners of land that is subject to soil erosion to leave it uncropped. Although only about 6% of Wisconsin’s agricultural land is in the CRP, a lot of this land is in southwestern Wisconsin. Here in the Driftless area, cropland is highly erodable and much of it is not of high fertility. Land owners are paid to take this land out of production. This not only protects the land from erosion, but it also improves water quality and wildlife resources.

We had placed all of our agricultural fields in the CRP in 1987, and it had been untilled after that time. When our CRP contract was renewed in 1997, we elected to establish prairie on these fields. This gave us the possibility of encouraging species that "should" have been present somewhere at Pleasant Valley Conservancy but were not. Often these missing species had been lost due to grazing or other agricultural practices.

One of the practices encouraged by the CRP is planting native prairie. Over 6,000,000 acres of CRP land have been planted to prairie throughout the country. Although the focus of the CRP is on native grasses, we elected to plant not just grasses but a complete "prairie", with over 60 species on each site. Although many landowners purchase seed from commercial seed growers, we elected to use seed that came only from our own prairie remnants, or from nearby sites. The prime reason was to ensure that we were using seed of local genotypes. Restoration ecologists believe that local genotypes are better adapted and perhaps less aggressive.

 

 

Steps in Prairie Planting

The steps we used in prairie planting are: 1) Preparation of the field for planting; 2) Collecting seed from suitable sites; 3) Handplanting, usually in the late fall of the year; 4) Mowing or handweeding for the first year or two after planting; 5) Conducting controlled burns annually, beginning as soon as there is sufficient fuel to carry a fire; 6) Continued handweeding until the prairie is well established.

It is important to understand the life cycle of a prairie plant. Most prairie plants have extremely deep root systems, and the first year after seed germination, the plant expends most of its energy in making roots. Research has shown that mature plants of most prairie species have root systems several to many feet deep. It is only because of the deep root system that prairie plants can survive the common droughts of summer. Thus, the first year after planting, prairie plants may grow only an inch or two, but develop good root systems. Most of the greenery that appears the first growing season of a new prairie is due to weeds, primarily shallow-rooted annual or biennial weeds that develop from the existing seed bank. It is only after the second or third growing season that good prairie plants are visible, and it may take five, six, or more years for some of the more conservative prairie species, such as compass plant, lead plant, and shooting star, to become established. Thus it is important to have patience. Even more important, it is necessary to discourage the growth of weeds until the prairie species have become well established. These principles guide the steps in prairie creation outlined below.

Preparation of the field Fields that remain fallow in southern Wisconsin usually revert to nonnative species, both grasses and forbs. The primary grass in our fields was smooth brome (Bromus inermis), with nonnative forbs such as Queen Anne's lace (Daucus carota), ox-eye daisy (Leucanthemum vulgare), wild mustard (Brassica nigra), and red clover (Trifolium pratense). Except for a few corners, there was nothing "good" on these fields. To prepare the field for planting, this nonnative vegetation was removed by spraying three times with glyphosate, a nonspecific herbicide. For the first spraying, the herbicide 2,4-D, which is active only against broad-leaved plants, was also added to the spray mix.

Seed collection Seeds for the planted prairies were collected from remnants elsewhere on the property, or from nearby sites. Fortunately, Pleasant Valley Conservancy had significant populations of two major native prairie grasses, Indian grass (Sorghastrum nutans) and little blue stem (Schizachyrium scoparium). We also had good populations of many prairie forbs. A few desirable forbs not available in the area were obtained by trade from other prairie sites in southern Wisconsin. Seeds were cleaned to remove stems and extraneous matter. Seed collecting procedures are discussed on another page.

Handplanting Volunteers planted the fields by hand in mid November. Seeds to be planted were weighed to ensure adequate densities and then mixed with sawdust to ensure good distribution. The fields were marked into uniform small plots and each volunteer was assigned a plot.

 
Volunteers relax after planting the Pocket Prairie. See photos above for "before and after" shots.

 

Mowing As noted, the first year on a planted prairie is a year of weeds, lots of them. Since the prairie plants are only an inch or so tall, mowing does not hurt them. Rather, it keeps the field open so that the prairie plants receive good sunlight. We hired a local farmer to mow our planted fields. The mower height was set to about 4 inches, short enough to cut the weeds, but tall enough so the prairie plants are not cut. The timing of mowing depended upon the prairie, the weather, and the kinds of weed species in the seed bank. Mowing two or three times the first growing season was always required. In some cases, we had to mow part or all of the "prairie" during the second year. For two prairies, the whole field did not need to be mowed, but only those areas where undesirable weeds were most prevalent.

Handweeding Once mowing is discontinued, weed control must be done by hand. (Use of herbicides is not advisable, because it will eliminate desirable species as well.) Handweeding is one of those chores of prairie restoration that seems to go on forever, and in fact, this is the case. Even if the field was completely free of weeds at the start, there will still be a weed problem. Some pesky weeds we had were: sweet clover (Melilotis alba), wild parsnip (Pastinaca sativa), Queen Anne's lace (Daucus carota), and mullein (Verbascum thapsis). Fortunately, all of these are biennials, and could be pulled relatively easily in their second year of growth. It is important that they be pulled at the time of flowering, but before seed set. If we had to pull them when they were setting seed, then we bagged the plants removed them from the field.

Controlled burns By the third growing season, prairie grasses should be established sufficiently so that controlled burns are possible. Controlled burns are vital. They discourage exotic plants and encourage the growth of prairie plants. Early spring burns are best, and they should be continued annually for five or six years. Once the prairie is well established, burn frequency can probably be reduced to once every two to three years, although it usually does not hurt to burn a planted prairie annually indefinitely. We have continued burning our planted prairies even after they had become well established. Burning stimulates growth of prairie plants, and greatly promotes production of viable seed. We used the seed produced by the first-planted prairies for the later-planted ones.

Contrast between burned (right) and unburned (left) parts of a planted prairie. The grass is primarily Indian grass. The burn was done the previous year. Toby's Prairie in late winter 2007.

 

Monitoring A planted prairie should be monitored carefully to determine what species are present, and to detect new species when they first appear. Some species may not show up for six or more years. Monitoring is also essential to catch weed problems. Once a prairie has been well established, it now becomes a source of seed collection for planting other fields. This process can go on indefinitely.

Skill is needed to recognize prairie plants during their first year or two. Unfortunately, the only way to obtain this skill is by learning from experts. For this reason, we recommend attending frequent field trips and participating in volunteer workday activities.

One of the principles of prairie restoration is that the perennial prairie plants will eventually outcompete the weeds. In a tall-grass prairie, the native species create prairie sod, which keeps weed seeds from growing. Also, the tall grasses shade out the weed species, inhibiting their growth. Careful monitoring will provide useful insights into this competitive situation.

 

Planted Prairies at Pleasant Valley Conservancy

 

The five agricultural fields planted to prairie are shown in blue on the management map. Four of these fields are in the CRP. Two of these fields are on the ridge top and are fairly dry, whereas the other three fields are at or near the bottom lands and are mesic to wet mesic. For convenience, these fields have been given names. All five of these fields have been planted. Those prairies that have had a chance to develop are each covered on a separate web page (links below).

We have also planted two additional area which had not been in the CRP. Both are adjacent to the wetland, had at one time been tiled and planted. One small field (the Barn Prairie) had been cropped but was too small for the CRP.

The other had not been cropped for many years. The tile field was long gone and the whole area had brushed in heavily. In addition to a huge honeysuckle population, there were many walnuts and cherries. All of this area was cleared in the winter of 2004-2005. In the summer of 2005 it was treated twice with glyphosate to kill perennial weeds and it was handplanted in Decembery 2005. Because of its location adjacent to the wetland, it was planted with a wet-mesic prairie mix. Because we often see sandhill cranes in this area, it has been named Sandhill Crane Wet Prairie (Crane Prairie for short).