Ground ivy was one of the few plants that had ideal growing conditions in 1993. Needless to say, homeowners are trying to eliminate it this spring. Ground ivy (Glechoma hederacea) is an aggressive, low-growing, perennial invader of lawns, vegetable gardens, and flower beds. It thrives in moist, shady areas, as well as sunny locations. The scalloped leaves are round or kidney-shaped and are attached by petioles to square stems. Ground ivy roots at each joint whenever it touches the soil, thus making it difficult to hand pull. The small flowers are funnel shaped and bluish-purple in color.
Preemergence herbicides do not control ground ivy, accordingly, we are left with postemergence controls. The most effective control comes with the use of combination herbicides that contain the product dicamba. The best time to achieve good control is in the fall, from mid-September to early November. The next best time to control ground ivy is when it is just beginning to flower. This occurs towards the end of April. Two herbicide applications, spaced 10 to 14 days apart are usually necessary to achieve good control. Care must be taken when applying broadleaf herbicides in the spring. The succulent growth of sensitive broadleaf plants can easily be injured by spray drift or volatilization of broadleaf herbicides. Apply the products when winds are calm and when temperatures are below 85oF for a few days. With many broadleaf herbicides, it is necessary to wait 4 weeks or longer before reseeding. They cannot be used for controlling weeds in vegetable or flower gardens. Always read and follow label directions carefully when applying pesticides.
Many ground ivy infestations are too severe to control successfully through broadleaf herbicide applications. Complete renovation of an infested area is another alternative. Repeated tilling or an application of a non-selective herbicide product containing glyphosate will kill ground ivy. It may be necessary to treat the area twice with the glyphosate product before the weed is completely killed. Lawn seeding can be done 7 days after application. The best time to attempt lawn renovation is mid to late summer. Seeding should be completed before mid September.
Ground ivy, though difficult, can be successfully removed. Once you've gone through the work of eliminating it, good mowing, fertilization, and cultural practices will help keep it out of the lawn. In flower and vegetable gardens, keep a plant-free zone at the edge of the garden to allow for easy control of invasive weeds before they spread into desirable plantings.
This article originally appeared in the April 6, 1994 issue, p. 48.