Creeping Charlie, formally known as Glechoma hederacea, is a persistent, low-growing broadleaf weed that can quickly dominate a lawn. This perennial plant, also called ground ivy, spreads aggressively through stolons, which are horizontal stems that root at the nodes, forming dense mats. Successful control relies heavily on precise timing because its protective, waxy leaves resist herbicide absorption. The herbicide must be absorbed and moved throughout the plant’s internal system to reach the roots.
Identifying the Most Effective Treatment Windows
The process of nutrient movement within the plant, known as translocation, dictates the most effective time for herbicide application. A systemic herbicide must be applied when the plant is actively moving substances downward to its root structure to maximize effectiveness. This downward movement provides a direct pathway for the chemical to reach and destroy the extensive root system.
The single most effective period for treatment is the fall, generally from late September through late October, before the first hard freeze. During this time, the plant is actively growing, but cooling temperatures signal it to begin storing energy reserves for winter. This natural energy storage process maximizes the transport of the herbicide from the leaves down to the roots, ensuring a complete kill.
A secondary window for application exists in the spring when the plant is actively growing and flowering, typically in April or May. Although the plant is actively absorbing nutrients, the energy flow is primarily directed upward to support new growth. Spring applications are less effective than fall treatments because less herbicide is pulled down to the root system. Spring treatments often require a follow-up application to manage the infestation.
Spraying during the peak of summer heat should be avoided, as the plant can become stressed or go partially dormant during dry conditions. When the plant is not actively growing, it will not efficiently absorb or translocate the herbicide, making the application ineffective. Applying herbicides when temperatures are consistently above 85°F can also increase the risk of damaging the turfgrass.
Selecting the Right Herbicide for Ground Ivy
Creeping Charlie is resistant to many common broadleaf weed killers, requiring specialized chemical formulations. The waxy layer on the leaves demands an herbicide designed to penetrate this barrier and be absorbed efficiently. The most effective products contain a combination of selective broadleaf herbicides.
Look for products that include two or three of the following active ingredients:
- 2,4-D
- MCPP (Mecoprop)
- Dicamba
- Triclopyr
Triclopyr is often cited as the most potent ingredient against ground ivy, offering superior control compared to 2,4-D alone. Using a combination of these ingredients attacks the weed with different modes of action, increasing the chance of complete eradication.
Liquid concentrate products are preferred over granular weed-and-feed products for controlling this weed. The liquid formulation ensures better coverage of the low-growing leaves, which is crucial for absorption. For maximum efficacy, consider adding a non-ionic surfactant (spreader/sticker) to the spray mixture. This additive helps the herbicide solution stick to and penetrate the waxy leaf surface, so always follow the label instructions for safety and the correct application rate.
Essential Application Techniques and Follow-Up
Proper preparation before spraying ensures the herbicide is absorbed effectively by the weed. Mowing the lawn a few days before application is recommended to reduce the canopy height and expose more of the weed’s leaf surface to the spray. If the area is dry, lightly watering the treatment area 24 hours prior can encourage the plant to be more active and absorb the chemical.
The application should be done on a calm day with little to no wind to prevent herbicide drift from reaching desirable plants. Optimal air temperatures for application are between 50°F and 80°F, which encourages active plant growth and absorption without stressing the turf. Check the forecast to ensure no rain is expected for at least 24 to 48 hours following the treatment, allowing the product sufficient time to be absorbed.
Following the application, a waiting period is necessary to allow the herbicide to translocate to the root system. Do not mow the treated area for at least two days after spraying, and avoid watering the lawn for 24 to 48 hours. For heavy infestations, a second application should be made approximately 10 to 14 days after the first. This sequential treatment is necessary to control the weed and prevent its re-emergence.
Long-term control relies on maintaining a healthy, dense lawn that can outcompete the weed. Proper fertilization, especially in the fall, and mowing the turf at a higher setting (around three inches) will help the grass thicken and discourage Creeping Charlie from re-establishing.