Managing Ground Ivy and Violets in Lawns

Lawns in shade areas are rarely very vigorous or dense and thus may be prone to weed invasion. Two of the more common broadleaf weeds invading shade lawns are ground ivy and violets. Both are very difficult to control.

Ground ivy (Glechoma hederaceae), also called creeping Charlie, is a common lawn weed problem. Lawns in shaded areas and often with poorly drained fertile soil are typical sites for ground ivy to develop into a major problem. This plant may form extensive patches as it creeps along the soil and can move into sun areas. Stems are square. Leaves are arranged opposite of each other along stems, and are round to somewhat kidney shaped with rounded, toothed margins. Crushed leaves have a minty odor. Ground ivy has small funnel-shaped purplish-blue flowers appearing from April to June.

Violets (Viola species) include several cool-season annuals and perennials that are low-growing plants. These species are very shade tolerant and prefer lawns located on moist, fertile soils. Violets tend to be most visible during cool weather of spring and fall. Leaves of the common violet are oval to kidney-shaped with a heart-shaped base. Flowers may be white, blue, purple, or yellow. All violets reproduce by seed, and perennial violets also spread by creeping roots and rhizomes.

To keep ground ivy and violets from invading lawns, maintain a thick lawn by proper lawn care practices. Unfortunately, grasses in shade areas are not as competitive against weeds as those in full sun. Reduce shade by pruning (see Managing Lawns in Shade Areas). In some shade situations, the ground ivy actually functions quite well as a groundcover. Likewise, violets may be desirable in some woodland areas.

One control option is to dig out existing ground ivy or violets. Pull up all the roots and stems or the plant will grow back.

Although control is difficult, existing ground ivy and violets can be treated with postemergence broadleaf herbicides in the period from mid spring to early summer and/or mid to late fall. Regardless of the time, make sure the weeds are actively growing. For ground ivy, suggested herbicides contain dicamba. Three-way broadleaf herbicide combinations (one product containing all three herbicides) that include 2,4-D (2,4-dichlorophenoxyacetic acid); mecoprop or MCPP (2-(2-methyl-4-chlorophenoxy) propionic acid); and dicamba (3,6-dichloro-o-anisic acid) may provide the best control. Several of these three-way herbicides are available (Trimec, Three Way Lawn Weed Killer, etc.); check product labels for these active ingredients. Read and follow all label directions. Herbicides containing 2,4-DP or triclopyr may also be effective. For violets, broadleaf herbicides containing triclopyr are suggested. Professional turfgrass specialists available for hire may use products containing 2,4-DP or triclopyr. Refer to the Illinois Commercial Landscape & Turfgrass Pest Management Handbook for details on these herbicides.

For more assistance on identifying weeds in midwest lawns, go to the Midwest Turfgrass Weed Identification and Control website.