Creeping Charlie, or Glechoma hederacea, is an aggressive perennial weed that presents one of the most frustrating challenges for lawn owners. This plant is a member of the mint family and is notorious for its ability to quickly spread and establish dense, carpet-like mats in turfgrass. Successfully removing and preventing its return requires a targeted, multi-step strategy. This strategy combines chemical treatment, physical removal, and careful changes to lawn care practices.
Identifying the Problem Weed
Recognizing Creeping Charlie is the first step toward effective control. The plant features distinctive square stems, a characteristic of the mint family, and kidney-shaped or round leaves with scalloped edges. These bright green leaves grow opposite one another along the creeping stem, called a stolon.
The plant’s aggressive nature comes from its ability to root at every node along these stolons, allowing it to rapidly spread and form a dense ground cover. This growth pattern makes physical removal difficult, as any small piece of stem left behind can re-establish itself. Additionally, the leaves have a waxy surface that causes many standard herbicides to bead up and run off, preventing chemical absorption.
Targeted Chemical Eradication
Chemical control is often necessary for widespread infestations. Success hinges on using the correct active ingredients and precise application timing. The most effective broadleaf weed killers contain the active ingredient triclopyr, which is highly systemic. A reliable option is a “three-way” herbicide blend, which typically combines 2,4-D, dicamba, and MCPP (mecoprop).
Avoid single-ingredient products containing only 2,4-D, as these do not provide adequate control against the root system. The herbicide must be absorbed by the leaves and transported down to the stolons and roots to ensure the entire plant is killed.
The timing of application is a determining factor in the herbicide’s effectiveness, since the plant must be actively moving nutrients. The most effective period is in the early fall, typically late September through October, after the heat of summer has passed. During this time, the weed is preparing for winter by moving carbohydrates down to its roots for storage, which simultaneously pulls the herbicide into the root system.
A second application in the spring, before or during the plant’s flowering period (April to June), can enhance control. Always follow the label instructions strictly regarding application rates and temperatures to avoid damaging desirable turfgrass. Applying when temperatures are moderate and the plant is not under drought stress ensures maximum absorption.
Natural and Manual Removal Methods
For smaller, isolated patches, physical and natural removal methods can be used, though they require persistence. Hand-pulling can be effective, but it demands extreme thoroughness to ensure no stem fragments remain in the soil. Since Creeping Charlie roots at every node, even a small piece of a stolon can quickly sprout into a new plant.
Smothering involves covering the affected area with materials like black plastic sheeting or thick layers of cardboard for several weeks. This blocks light and starves the plant, but it will also kill the underlying turfgrass. This technique is best reserved for areas where reseeding or replanting is planned after the weed is gone.
The use of Borax (sodium tetraborate) is sometimes suggested because Creeping Charlie is highly sensitive to the micronutrient boron. Boron is essential for plant growth only in minute quantities, and an excess becomes toxic. The goal is to apply a dose high enough to kill the weed but low enough not to harm the surrounding turfgrass.
This method carries a high risk because the margin for error between an effective dose and a toxic dose for grass is extremely narrow. Boron does not easily break down or leach out of the soil and can accumulate, potentially preventing plant life for years. A professional soil test is necessary to determine if Borax can be safely used and at what precise concentration.
Cultural Practices for Long-Term Control
After the initial eradication, maintaining a dense, healthy lawn is the most effective long-term defense against the weed’s return. Creeping Charlie thrives in environments where turfgrass is weak, favoring moist, shady conditions and compacted or nutrient-poor soil. By changing the environment, you make the area less hospitable for the weed.
The primary change is to raise the mowing height to between three and four inches. Taller grass blades shade the soil surface, which discourages the growth of Creeping Charlie. A taller turf canopy also promotes a deeper root system, making the grass more competitive.
Improving soil health is crucial, particularly by addressing compaction and drainage issues. Aerating the lawn in the fall or spring reduces soil density, allowing grass roots to grow stronger and helping water drain more effectively. Reducing surface moisture through better drainage and mindful watering practices will further hinder its establishment.
Proper fertilization encourages a thick, vigorous turf that can physically crowd out the weed. A consistent fertilization program, often involving nitrogen applications in the spring and fall, strengthens the grass. These cultural practices create a sustainable environment where turfgrass naturally outcompetes the invasive weed.