Creeping Charlie, also known as ground ivy (Glechoma hederacea), is a perennial broadleaf weed that can quickly overwhelm a lawn. It spreads aggressively via above-ground runners called stolons, which root at every node they contact with the soil. This creates a dense, resilient, mat-like patch. Creeping Charlie thrives in shady, moist, and often poorly maintained turf, allowing it to easily crowd out grass. Homeowners must employ non-synthetic, organic methods that are both targeted and comprehensive for successful eradication.
Manual Removal and Cultural Control Methods
The most direct organic approach to controlling Creeping Charlie involves physical removal, which is best performed when the soil is moist to facilitate the extraction of the root system. When hand-pulling, grasp the main stems and gently trace the runners back to where they root. Ensure you remove the entire stolon network and as many of the shallow roots as possible, as even small fragments left behind can regrow.
In non-lawn areas or beds heavily infested with the weed, smothering or solarization can be used. Smothering involves depriving the plant of sunlight by covering the area with a dark, opaque material like wet cardboard, followed by a thick layer of organic mulch. For a more intensive kill, clear plastic sheeting can be used during warm months to trap solar heat, destroying the weed and its seeds.
Adjusting lawn maintenance practices, known as cultural control, helps to create an environment that discourages Creeping Charlie growth. Raising the mowing height to between three and four inches allows the turfgrass blades to grow taller and cast shade on the soil. This reduces the light reaching the low-growing weed, making it harder for it to establish and spread. Improving surface drainage can also eliminate the excessive moisture that Creeping Charlie prefers, weakening its foothold in the lawn.
Targeted Organic Application Solutions
For infestations too large for simple hand-pulling, certain organic products and home remedies can be used as targeted spot treatments.
Iron-Based Herbicides
Iron-based herbicides use chelated iron as the active ingredient. Broadleaf weeds like Creeping Charlie absorb this iron compound much faster and in higher quantities than turfgrass. This leads to iron oxidation and plant necrosis, causing the weed foliage to turn black and shrivel within hours. This approach is selective because the grass absorbs the iron more slowly, remaining unharmed and often benefiting from the nutrient.
Borax Solution
A traditional home remedy involves applying a solution of Borax, or sodium tetraborate. Creeping Charlie is sensitive to the micronutrient boron, which acts as a toxin in minute excess by interfering with its metabolic processes. Extreme caution must be exercised, as the margin of safety between the amount that kills the weed and the amount that sterilizes the soil is narrow. Typically, 10 ounces of Borax are dissolved in warm water, then diluted into 2.5 gallons of water to cover approximately 1,000 square feet.
Horticultural Vinegar
Horticultural vinegar contains a higher concentration of acetic acid than household vinegar. Acetic acid works as a non-selective contact herbicide, rapidly desiccating the plant tissue it touches. This method is best reserved for non-lawn areas like sidewalks or garden beds, as it will also damage or kill turfgrass. Since vinegar does not typically travel down to the root system, multiple applications are necessary to cause complete dieback and prevent regeneration.
Long-Term Strategies for Turf Resistance
Improving the overall health and density of the turfgrass makes the lawn a highly competitive environment against Creeping Charlie. This weed often signals that the soil is compacted and potentially low in nutrients, so addressing these underlying conditions is necessary. Conducting a soil test can reveal the soil’s pH level. Since Creeping Charlie tolerates slightly acidic conditions, applying lime may be recommended to raise the pH closer to the optimal range of 6.0 to 7.0 for most turfgrass species.
Aeration, the process of removing plugs of soil, reduces compaction and allows for better air, water, and nutrient movement into the root zone, strengthening the grass. Following aeration, overseeding with a dense, shade-tolerant grass variety, such as fine fescue, fills in thin areas where the weed would otherwise easily establish. A dense turf canopy shades the soil surface, effectively blocking the light Creeping Charlie needs to germinate and spread its runners.
Proper fertilization timing and type also promote robust grass growth over weed establishment. Applying a slow-release nitrogen fertilizer in the fall, when grass roots are actively growing, helps the turf thicken up and outcompete weeds the following spring.