Creeping Charlie (Glechoma hederacea) is an aggressive, low-growing perennial weed that often invades lawns and garden beds. This member of the mint family spreads rapidly using vining stems called stolons, which root down at every node they touch. This growth habit, combined with its resistance to many common herbicides, makes it difficult to control once established. For those seeking non-toxic solutions, a combination of physical removal, environmental modification, and careful natural applications provides a path to eradication.
Manual and Mechanical Removal Strategies
Physical removal is the first step in controlling Creeping Charlie to immediately disrupt its extensive network of runners. Hand-pulling is the most direct method, but it requires meticulous attention because the plant regrows easily from small fragments. Grasp the main stem and gently follow the runners, ensuring you remove the entire stolon and all associated roots from the soil.
The plant’s resilience stems from the nodes along its stems, which quickly root when they contact the soil. Missing a single node or leaving a fragment of the stem in place means the plant will easily reestablish itself. For larger, dense patches, using a hand cultivator or a trowel to loosen the soil before pulling can help you extract the entire shallow root system intact. Always dispose of the pulled plant material in the trash, not the compost pile, to prevent any remaining fragments from re-rooting elsewhere.
For areas that are heavily infested and not part of a manicured lawn, a mechanical method like solarization can provide an effective, large-scale solution. This process involves covering the affected soil with a clear plastic sheet for several weeks during the hottest part of the summer. The clear plastic traps solar energy, raising the soil temperature high enough to kill the weed and its seeds beneath the surface. While highly effective, solarization is an extreme measure that sterilizes the soil, killing both beneficial organisms and the weeds.
Adjusting Cultural Practices to Suppress Growth
Achieving long-term control of Creeping Charlie depends heavily on altering the environmental conditions that allow it to thrive. This weed prefers consistently moist, shady environments and often takes hold in turf that is already weakened. By improving your lawn’s health and density, you can create a hostile environment that favors grass growth over the weed.
One of the most powerful defenses against Creeping Charlie is proper mowing height. Mowing the grass at a height of at least three inches encourages the turf to develop a deeper, stronger root system and creates a dense canopy. This taller grass effectively shades the soil surface, blocking the sunlight that the low-growing weed needs for photosynthesis and suppressing its lateral spread.
The plant’s preference for damp soil means adjusting watering habits is also an important cultural change. Instead of frequent, shallow watering that keeps the soil surface moist, switch to deep, infrequent watering. This practice allows the top layer of the soil to dry out between watering sessions, which discourages the weed while encouraging the grass roots to grow deeper, improving their drought tolerance.
Creeping Charlie frequently establishes itself in areas with poor soil health, particularly where the soil is compacted or low in nitrogen. Conducting a soil test can reveal underlying nutrient deficiencies or pH imbalances that favor the weed. Aerating compacted soil and topdressing with organic matter, like compost, improves drainage and helps create a better environment for healthy turf to outcompete the weed.
Since the weed flourishes in shade, increasing light penetration is another strong preventative measure. Thinning the canopy of overhanging trees or pruning lower branches allows more sunlight to reach the ground. More light promotes thicker grass growth in those previously shaded areas, reducing the opportunity for the weed to gain a foothold. Aggressively overseeding with a shade-tolerant turfgrass variety in the fall creates a denser stand of grass, which is the best defense against any invasive groundcover.
Utilizing Targeted Natural Treatments
While cultural practices provide long-term prevention, natural substances can be used as targeted treatments to eliminate existing patches. These applications require careful and precise use to avoid damaging surrounding desirable plants. High-concentration horticultural vinegar (approximately 20% acetic acid) is one option for spot treatment.
This highly acidic vinegar acts as a fast-acting, non-selective contact herbicide that destroys the plant’s foliage upon application. Since it is non-selective, it will kill any grass or other plants it touches, making it best suited for treating patches in garden beds or along edges. For best results, apply horticultural vinegar on a warm, sunny day, as the heat enhances its desiccating effect.
Another treatment involves borax (sodium tetraborate), which exploits the weed’s unusual sensitivity to boron. Creeping Charlie is susceptible to boron toxicity at levels that turfgrass can sometimes tolerate, though this method is controversial due to the risk of soil contamination. The accepted dosage involves dissolving 10 ounces of borax in warm water, then diluting the mixture into two and a half gallons of water to treat 1,000 square feet of lawn.
Apply borax with extreme caution, as boron does not dissipate or break down easily and can accumulate into toxic “hot spots.” An incorrect dosage or repeated application can severely injure or prevent future plant growth in the treated area. Note that corn gluten meal, which prevents seed germination, is ineffective against Creeping Charlie, which spreads primarily through runners.