Some of the most common perennial broadleaf weeds in Missouri lawns include bindweed, chicory, creeping bellflower, dandelion, ground ivy, mouseear chickweed, plantain, thistle, violets, and white clover. They differ from annual weeds in that they continue to grow year after year and once established, they are not affected by preemergent herbicides.
NOTE: See separate sheets for more information on controlling violets, yellow nutsedge, or wild garlic and onions.
Integrated Pest Management Strategies
1. Hand dig or spot treat. If only a few weeds are present, hand dig the weeds with a forked tool to cut the root off well below ground level. You can also spot treat using glyphosate (Roundup, Kleenup) or the chemicals listed below. Since glyphosate (Roundup, Kleenup) is NOT selective, it will also kill any grass you get it on so apply very carefully. This method works best with weeds such as thistle or large plantain plants. The herbicide can also be brushed on individual weeds, avoiding the grass. NOTE: 2,4-D products listed below used according to label directions will not damage grass caught in the overspray.
2. Use chemical herbicides. When problem areas are too large for spot treating, hose-end products are the easiest for homeowners to use. Garden centers and hardware stores carry many different brands that contain various combinations of 2,4- D, MCPA, MCPP, and dicamba, weed killers that control broadleaf weeds. First establish the identity of the weeds, then check product labels to determine which herbicide best controls the weeds you have. Then, be sure and follow label directions. Some weeds may require more than one application. Perennial weeds are best killed when they are actively growing, which is usually in spring and fall. Herbicides applied in the summer are usually less effective.
3. Shade out the weeds. Areas of weeds can also be killed by covering the affected areas with black plastic, felt paper, boards, or cardboard until the weeds are dead. This will kill all plants that are shaded, including both desirable and undesirable perennial grasses. This may take several weeks. The killed areas will need to be tilled and reseeded or sodded at a later date.
(The following Weed ID pages linked to with permission of UMass Extension.)
Strategy 3 is a strictly organic approach. Hand digging, as suggested in Strategy 1, is an organic approach.