Glechoma hederacea, commonly known as Creeping Charlie or ground ivy, is a highly aggressive perennial weed and an invasive species in many parts of North America. A member of the mint family (Lamiaceae), it quickly forms dense, low-growing mats that aggressively choke out desirable turf grass and other plants. Its rapid spread is driven by both seeds and vining stems, known as stolons, which root easily at the nodes as they creep across the ground.
Identifying the Invader
Accurately identifying this plant is the first step toward effective control. Creeping Charlie is characterized by bright green leaves that are round or kidney-shaped with distinct scalloped edges. These leaves grow opposite each other on long leaf stalks.
A defining feature of this weed, shared with other members of the mint family, is its square-shaped stem. When crushed, the plant releases a strong, pungent minty aroma. During the spring, it produces small, bluish-purple or lavender flowers.
Understanding Its Preferred Environment
Creeping Charlie thrives in specific environmental conditions that often weaken turf grass, allowing the weed to gain a foothold. It has a strong preference for moist, shady areas where soil drainage is poor, often found under trees or in poorly maintained lawns.
While it prefers shade, the plant is adaptable and can tolerate full sun if soil moisture remains high. The presence of this weed often indicates that the lawn area is compacted or has low soil fertility, favoring the weed over healthy turf. Its aggressive spread is particularly successful where the grass canopy is thin, allowing it easy access to soil and light.
Non-Chemical Management Techniques
Managing Creeping Charlie without herbicides involves improving the turf’s health and physically removing the plant. For small, isolated patches, manual removal is possible, but it requires diligent effort to remove the entire plant and its root system. Since the horizontal stems root at every node, leaving behind even a small fragment leads to regrowth.
Long-term control relies on cultural practices that make the environment less hospitable to the weed. Improving soil health by aerating compacted areas and ensuring proper drainage reduces the excessive moisture the plant loves. Raising the mowing height to between two and three-and-a-half inches encourages a dense, tall turf canopy. This thicker grass helps shade the soil and starves the low-growing Creeping Charlie of needed sunlight.
Another non-chemical option for heavily infested areas is solarization or smothering. This involves covering the patch with a thick layer of cardboard, newspaper, or black plastic to block all sunlight. This technique kills the weed by overheating and preventing photosynthesis, though it may take several weeks or months. After the weed is dead, the area should be reseeded with a shade-tolerant turfgrass variety to prevent re-infestation.
Targeted Eradication Strategies
When cultural methods prove insufficient, a targeted chemical approach is often necessary for complete eradication. The most effective control uses postemergence broadleaf herbicides containing specific active ingredients. Look for products containing triclopyr or a combination of 2,4-D and dicamba, as these compounds are highly effective against ground ivy.
Creeping Charlie has waxy leaves that resist herbicide absorption, making application timing crucial. The most effective time for treatment is in the late fall, after the first light frost. At this time, the plant is actively moving nutrients down to its roots for winter dormancy, allowing the herbicide to be transported throughout the entire root system.
A second application should be made in the early spring when the plant is actively growing and flowering, usually between April and June. Due to the waxy leaf surface, using an herbicide that includes a surfactant helps the chemical penetrate the foliage more effectively. Apply treatments when temperatures are moderate (mid-60s to low 80s) and when no rain is expected for at least 24 hours to maximize absorption.
Because a single application rarely achieves complete control, a sequence of treatments is required over one or two seasons. Multiple applications ensure that any surviving root fragments or newly germinated seeds are targeted. Following chemical treatment, immediately implement cultural practices to improve turf density and prevent return.