Ground ivy (Glechoma hederacea), also known as creeping Charlie, is a perennial broadleaf weed known for its aggressive, low-growing nature, making it difficult to control in lawns. This plant is a member of the mint family and spreads rapidly through horizontal stems called stolons that root at the nodes. The difficulty in selective removal stems from the plant’s waxy leaves, which repel many common herbicides. The challenge is finding a treatment that targets this hardy weed without damaging the surrounding grass.
Active Ingredients for Selective Removal
The ability to kill ground ivy while sparing turfgrass relies on selective broadleaf herbicides. These products exploit the physiological differences between dicot weeds, like ground ivy, and monocot grasses. The most effective treatments contain synthetic auxins, compounds that mimic natural plant hormones, causing uncontrolled and unsustainable growth in broadleaf plants.
Combination products often contain a mixture of ingredients such as 2,4-D, MCPP (mecoprop), and dicamba to maximize effectiveness against a wide range of broadleaf weeds. Triclopyr is frequently cited as one of the most potent active ingredients for targeting ground ivy specifically. These synthetic auxins disrupt the plant’s normal growth patterns, leading to distorted stems, malformed leaves, and eventual death.
Grasses, which are monocots, are naturally more tolerant of these synthetic auxins. They possess specialized vascular cells that prevent the uncontrolled growth effects from becoming lethal. This physiological difference allows the herbicide to be applied safely across a lawn, killing the weed but not the grass when used according to label instructions.
Optimizing Application Timing and Technique
The timing of herbicide application is important for effective control of ground ivy. The most successful treatments occur in the late fall, typically from late September through early November. During this period, the ground ivy is actively moving sugars down to its root system to prepare for winter. This allows the systemic herbicide to be efficiently translocated throughout the entire plant, including the extensive root network.
A secondary window for treatment is in the early to mid-spring when the plant is flowering. Due to the waxy coating on ground ivy leaves, ensure thorough coverage of the foliage during application. Using an ester-based formulation or adding a surfactant helps the chemical penetrate the protective leaf surface. Follow-up applications are almost always necessary, with a second treatment applied approximately four to six weeks after the first, or a repeat application the following spring.
Non-Chemical Control Methods
For small, isolated patches of the weed, manual removal remains a viable non-chemical option, provided the soil is moist. It is necessary to trace the stolons and remove the entire runner, roots and all, as any remaining rooted nodes can quickly regenerate the plant. For larger infestations, smothering the area with thick plastic or cardboard works by depriving the ivy of sunlight, though this method will also kill the grass underneath.
Some individuals attempt to use borax, which contains the micronutrient boron, as a non-chemical control method. Research has shown that ground ivy is sensitive to boron, but the margin of safety between the amount that kills the weed and the amount that damages turfgrass is extremely narrow. Using borax is risky because its effectiveness depends heavily on the soil’s existing boron content, making it rarely truly selective.
Cultural Practices for Long-Term Prevention
The most effective long-term strategy for preventing ground ivy is to create a lawn environment that favors turfgrass growth over weed establishment. Ground ivy thrives in unhealthy, thin turf, particularly in areas with excessive shade and poor soil drainage. By addressing these underlying conditions, the grass gains a competitive advantage that naturally suppresses the weed.
Increasing the mowing height to at least three inches encourages the grass to develop deeper roots and dense growth, which shades the soil and inhibits the ground ivy’s ability to spread. Consistent nitrogen fertilization strengthens the turf, allowing it to crowd out the invasive weed. Improving soil health through core aeration and addressing drainage issues reduces the moist, compacted conditions that ground ivy finds ideal for colonization.