2. Mowing - If dense weeds such as giant foxtail develop, mow the plot at a height of 8 to 12 inches with a rotary mower when the weeds reach a height of two to three feet. In the case of sweet clover, mow while the plants are flowering. It is important to use a rotary mower because of its shredding action. The vegetation cut by sickle type mowers could smother the seedlings of the prairie plants. Mow only those parts of the planting that have a weed problem.
3. Herbicides - The use of a selective herbicide for broadleaf plants can have application when there are scattered, dense stands of particularly troublesome weeds such as sweet clover. Care should be taken to avoid spraying desirable prairie plants. In the case of sweet clover, it can be sprayed early (March or April) before the prairie plants break dormancy. The sweet clover begins its growth early and it will be one of the few green plants on the restoration site (Schwegman and McClain 1985).
4. Fire - Prescribed burning helps to eliminate the alien cool season grasses and weeds. For this reason, a prescribed burn should be planned for March or April of the year following the planting of the prairie seed. Burning in the spring allows the prairie vegetation to remain throughout the winter providing excellent cover for wildlife during this critical period.
In the case of alien, cool season grasses such as bluegrass, late burns (early April) are more beneficial than burns conducted in February or early March. The same applies to sweet clover; early fires seem to stimulate the germination of seeds of this troublesome biennial. Burns conducted at the time of "bud break" may also prove to be helpful in reducing invasion by rough-leaved dogwood or other shrubs.