Post-harvest care for strawberry plants is a year-round process that determines the success of the following season’s yield. The main goal is to ensure the development of robust crowns, where next year’s flower buds will form, and to build up the plant’s carbohydrate reserves for winter survival. Plants must remain vigorous through the late summer and fall to secure a bountiful crop in the spring. This attention immediately following the final fruit pick is often called renovation, a step in maintaining a healthy, perennial strawberry patch.
Immediate Post-Harvest Plant Renovation
The first action after the final June-bearing strawberry is picked involves renovation, a physical renewal process. This step is reserved exclusively for June-bearing varieties because their short fruiting window allows enough time for new foliage to develop before fall flower bud formation. Renovation stimulates new, healthy growth that is more efficient at photosynthesis and helps control disease.
Renovation begins by mowing or cutting the old foliage approximately one to two inches above the crown, taking care not to injure the crown. Removing old leaves eliminates fungal spores and potential overwintering sites for pests, improving overall plant health. Simultaneously, matted rows must be narrowed, typically using a tiller, to a width of 10 to 15 inches to prevent overcrowding. This thinning ensures proper air circulation and sunlight penetration, which are necessary for new crown development and reducing disease pressure.
Runner management is also part of the renovation process for June-bearing plants, as overcrowding reduces berry size and yield. Excess runner plants rooted outside the narrowed row should be removed, leaving a density of no more than six plants per square foot. Day-neutral and everbearing varieties, which produce fruit continuously until frost, do not undergo mowing. Their renovation consists only of removing spent flower stalks, old yellowing leaves, and any runners to direct energy toward continued fruit production and crown strength.
Replenishing Nutrients and Water
After fruiting and renovation, plants have depleted their stored energy reserves, making immediate nutrient replenishment necessary. Fertilization stimulates vegetative growth for healthy new leaves and crowns before the plant shifts focus to fall flower bud formation. For June-bearing plants, a balanced fertilizer (e.g., 10-10-10 or 20-20-20) should be applied immediately after mowing and thinning.
The application rate is typically 10 to 20 pounds of balanced fertilizer per 1,000 square feet. A second, lighter application of nitrogen often follows in late August or early September to support flower bud development. Day-neutral and everbearing varieties require a continuous supply of nutrients due to their extended production, necessitating smaller, more frequent applications of a balanced fertilizer every four to six weeks until late summer.
Consistent moisture is important during the late summer and early fall months to support the development of strong crowns and the initiation of flower buds. Strawberry plants require approximately one to one and a half inches of water per week from rainfall and irrigation. Maintaining this moisture level is crucial immediately following renovation, as water is needed to activate the applied fertilizer and support the regrowth of new leaves.
Managing Pests and Weeds
Once renovation is complete and new growth begins, the focus shifts to sanitation and preventative care against overwintering threats. Old mulch, debris, and leaves removed during renovation can harbor fungal spores and insect eggs. Thorough removal of this debris and old mulch significantly reduces the inoculum for diseases that will emerge the following spring. Fungi responsible for common leaf diseases can survive the winter in this infected plant matter.
Pests like slugs, spittlebugs, and two-spotted spider mites can also overwinter in the sheltered environment of leaf litter. Hand-weeding or light, shallow cultivation around the plants is necessary to reduce competition for light and nutrients and to improve soil aeration without damaging the shallow root system.
Weeds compete with strawberry plants for the nutrients and water applied to encourage crown development. Removing them ensures the plants are the sole beneficiaries of post-harvest care, allowing them to build maximum carbohydrate reserves. This sanitation and weed management minimizes the severity of pest and disease outbreaks once the plants begin their growth cycle in the spring.
Preparing Plants for Dormancy
The final stage of post-harvest care involves preparing the plants for winter by applying a protective layer of mulch. The purpose of this mulch is not to keep the plants warm, but to keep the soil temperature stable and prevent freeze-thaw cycles. These cycles can cause shallow-rooted plants to be pushed out of the ground, a phenomenon known as frost heaving. Unprotected strawberry crowns can be damaged by temperatures below 15°F, which reduces the next year’s yield.
Timing the application of winter mulch is important; it should only be applied after the plants have hardened off and entered true dormancy. This typically occurs after several hard frosts, when air temperatures consistently drop below 20°F, or when the soil temperature at a four-inch depth remains at or below 40°F for three consecutive days. Applying mulch too early can trap heat and moisture, preventing the plants from properly developing cold hardiness.
Clean wheat or oat straw is the preferred material for winter protection because it is light, insulating, and does not mat down and smother the crowns like leaves or grass clippings. The straw should be spread loosely over the rows to a depth of four to six inches. This layer settles over the winter to provide adequate insulation, protecting the dormant crown and newly formed flower buds until spring, when the mulch is gradually removed as new growth begins.