Creeping Jenny (Lysimachia nummularia), also called moneywort, is a popular perennial groundcover native to Europe and western Asia. It is valued for its vibrant, low-growing foliage and ability to fill in difficult areas, but it has become widely naturalized across North America. Its aggressive growth habit causes it to quickly escape cultivation, transforming it into a persistent and difficult-to-control weed. Creeping Jenny forms dense, mat-like growth that chokes out desirable plants and turfgrass. It reproduces when its creeping stems root at the leaf nodes, making eradication a challenging process that requires a focused, multi-season approach.
Manual and Cultural Removal Techniques
For small, isolated patches, manual removal is a viable first step, provided it is done thoroughly. The plant adheres closely to the ground and possesses an extensive root system, even though the roots may be shallow. Hand-pulling must remove every segment of the stem and root, as any fragment left behind can easily re-root.
To manage larger infestations, cultural control methods that block light are effective because the plant does not grow well in shade. Solarization involves covering the affected area with thick black plastic sheeting for several weeks or months to use the sun’s heat to kill the plant material. Alternatively, applying a thick layer of organic mulch, at least 4 inches deep, can starve the plant of light. Mowing is generally ineffective because the plant grows low to the ground and its numerous rooting nodes allow it to survive the cut.
Targeted Herbicide Options
When manual and cultural methods prove insufficient, targeted chemical treatments are necessary for full eradication, especially for large or established areas. Creeping Jenny’s waxy leaves can make herbicide absorption difficult, requiring careful product selection and application timing.
Herbicides containing the non-selective active ingredient glyphosate are effective, but they will kill any plant they touch, necessitating precise spot-treatment. For selective control within a lawn, products containing broadleaf-specific herbicides are recommended, such as 2,4-D, dicamba, or triclopyr. Triclopyr is a systemic herbicide that moves through the plant to the roots, offering better control.
Optimal application timing is when the plant is actively growing in the early spring or, more effectively, in the fall. Applying in the fall is best as the plant prepares for dormancy and actively translocates resources to its roots.
A second application, typically six weeks after the first, is required to treat new growth emerging from surviving root fragments. Always follow the specific instructions on the product label for mixing, safety, and application rates. When treating areas near water, aquatic-approved formulations may be required. A non-ionic surfactant may be needed to help the chemical penetrate the plant’s protective leaf structure and ensure the herbicide contacts the foliage.
Post-Eradication Management
Complete eradication of Creeping Jenny can take two full growing seasons, making post-treatment management a long-term commitment. After any removal method, all plant debris must be disposed of properly to prevent re-establishment. Since the stems and root fragments can easily root, they should never be added to a home compost pile.
The treated area should be monitored regularly for any signs of new growth, which requires immediate follow-up treatment, either by hand-pulling or spot-spraying. Introducing competitive groundcovers or strengthening the existing turfgrass is a proactive measure that helps prevent the weed from returning. Filling the void with dense, hardy plants that can shade the soil will help block light and suppress the re-rooting of small fragments.