Strawberries (Fragaria) are notoriously difficult to eradicate completely from a garden or field. Their persistence comes from an aggressive reproductive strategy involving a substantial root crown and an extensive network of horizontal stems called runners, or stolons. These runners creep along the soil surface, rooting at nodes to form new, genetically identical daughter plants that quickly colonize an area. Permanent removal requires eliminating every piece of the root crown and all connected stolon fragments to prevent re-establishment.
Physical Removal and Tillage
The most direct, environmentally clean method for eradication involves intensive physical removal. Use a garden fork to carefully dig up the main crown of each plant, retrieving the entire root mass. Since strawberry roots can extend deep and wide, excavate an area slightly larger than the visible plant base.
After removing the main crown, the extensive stolon system must be traced and removed entirely. These long stems often root and form multiple daughter plants, each capable of starting a new colony. Any piece of a runner or root crown left in the soil can sprout again, necessitating a thorough sifting of the area.
Tilling the soil repeatedly brings remaining fragments to the surface where they can be collected and discarded. This labor-intensive process must be repeated over several weeks to capture missed fragments. This manual method ensures no chemical residue is left, making the soil safe for immediate replanting.
Using Environmental Methods for Eradication
Eradication can also be achieved using environmental conditions to stress and kill the plants. Solarization is a highly effective, non-chemical method that uses the sun’s heat to pasteurize the soil. This process involves thoroughly wetting the target area and covering it tightly with clear, four-mil polyethylene plastic sheeting during the hottest months.
The plastic edges must be sealed with soil or weights to trap moisture and heat. This raises soil temperatures in the top six inches to between 120 and 140 degrees Fahrenheit, which is lethal to strawberry crowns and many weed seeds. The plastic should remain in place for at least four to six weeks during peak summer heat to ensure complete kill.
Other Environmental Methods
A less aggressive approach is deep, opaque mulching, which smothers the plants by completely blocking light. This involves laying down a thick layer of cardboard followed by a minimum of six to eight inches of wood chips or other light-blocking material. This deprives the strawberry plants of the energy needed for photosynthesis. For small, isolated patches, pouring boiling water directly onto the crowns provides a quick, localized thermal treatment that destroys the plant tissue.
Targeted Chemical Application
If physical and environmental methods are impractical due to the size of the infested area, a targeted application of a non-selective systemic herbicide may be necessary. Products containing glyphosate are absorbed by the leaves and transported down to the root system, killing the entire plant. Selective herbicides are ineffective because strawberries are broadleaf plants.
The most effective application window is when the plants are actively growing, typically in the spring or early fall. During this time, the plants efficiently move nutrients and the herbicide throughout their system. The herbicide should be spot-treated directly onto the strawberry foliage to minimize impact on surrounding vegetation.
Always follow label instructions precisely regarding application rates and safety precautions. Safety requires using protective gear and careful application to avoid drift, especially near edible plants, water sources, children, and pets. Allow the herbicide several weeks to fully translocate and kill the roots before tilling or removing dead material. Multiple applications may be required for large patches to neutralize deep root crowns completely.
Ensuring Permanent Removal
Following initial eradication, a crucial period of monitoring and follow-up is necessary to prevent recurrence. Plant material must be disposed of properly and should never be placed in a home compost pile. Composting often fails to reach the sustained high temperatures required to kill these fragments, leading to reinfestation when the compost is used.
The treated area should be watched closely for several growing seasons, as small root fragments can remain dormant before sprouting new leaves. Any new sprouts must be immediately removed by hand or spot-treated with an herbicide to prevent re-establishment. For areas bordering existing strawberry patches, install physical root barriers or landscape edging sunk six to eight inches into the soil. This prevents future runners from crossing and re-colonizing the cleared space.