Ground ivy (Glechoma hederacea) is a common weed in many lawns. Ground ivy is a low-growing, creeping, invasive perennial. It spreads by seed and the vining stems (stolons) which root at their nodes. The leaves of ground ivy are round or kidney-shaped with scalloped margins. Stems are four-sided. Flowers are small, bluish-purple, and funnel-shaped. Ground ivy thrives in damp, shady areas, but also grows well in sunny locations. A member of the mint family, ground ivy produces a minty odor when cut or crushed. Ground ivy is also known as "creeping charlie."

Control of ground ivy in lawns is difficult. If the ground ivy is not completely destroyed, surviving portions will continue to grow and spread.

Recently, research at Purdue University investigated the effects of fertilization practices and several broadleaf herbicides on ground ivy. The research found that a good nitrogen fertility program and the use of herbicide products containing 2,4-D or triclopyr will help control ground ivy. (For many years, dicamba has been regarded as the most effective herbicide in controlling ground ivy. However, the Purdue University research found that 2,4-D and triclopyr are much more effective.)

The research also found that populations of ground ivy vary in their susceptibility to broadleaf herbicides. For example, one population of ground ivy may be highly sensitive to 2,4-D, while another population may be somewhat tolerant to 2,4-D.

Ground Ivy Control Strategy

Apply 3 to 4 pounds of nitrogen per 1,000 square feet per year. Nitrogen improves the vigor and competitiveness of Kentucky bluegrass, slowing the spread of ground ivy. An excellent fertilizer program for Kentucky bluegrass lawns consists of applications of 1 pound of nitrogen per 1,000 square feet in late April/May, September, and late October/early November.

Apply a broadleaf herbicide product containing 2,4-D or triclopyr to ground ivy infested areas. 2,4-D is an active ingredient in many broadleaf herbicide products. Triclopyr can be found in Ortho Weed-B-Gon Chickweed, Clover, and Oxalis Killer for Lawns and a few other products. Herbicide applications should be made between mid-September and November 1. Two applications are most effective. The second application should be made 28 days after the first.

Since ground ivy populations vary in their susceptibility to broadleaf herbicides, it is important to alternate herbicides when attempting to control ground ivy.
This article originally appeared on pages Page 1-2 of the IC-493(13) -- June 8, 2005 issue.