Winter covering, typically straw or pine needles, is applied in late fall to protect strawberry plants. Removing this insulating layer at the correct time in spring prevents plant damage and maximizes the potential berry harvest. Successfully uncovering strawberries requires monitoring both environmental temperatures and the subtle physiological changes occurring within the plants.
The Purpose of Winter Covering
Winter mulch primarily shields plants from the destructive effects of repeated freeze-thaw cycles in the soil. This constant expansion and contraction can physically push, or “heave,” the shallow-rooted strawberry crowns out of the ground. Exposed crowns are susceptible to desiccation and root damage, which can kill the plant or severely reduce productivity. The mulch layer acts as a temperature moderator, keeping the soil consistently cold and preventing this heaving. It also protects dormant flower buds within the crown from temperatures consistently dropping below 20°F (-6°C), which can cause irreversible damage.
Identifying the Critical Uncovering Time
The correct time to uncover strawberries balances protecting the plants from late frost and preventing them from suffocating. This moment typically arrives when the soil temperature, measured at two to four inches deep, consistently reaches 40°F (4°C). Sustained daytime air temperatures between 40°F and 50°F (4°C to 10°C) signal that deep winter cold has passed and growth is imminent. Leaving the mulch on too long after this point causes the plants to grow in the dark, resulting in weak, pale yellow foliage.
The most reliable indicator is the visual cue of new growth emerging from the crowns beneath the straw layer. These new leaves appear yellow or greenish-yellow due to the lack of light, signaling that the plant is breaking dormancy and requires immediate sunlight for photosynthesis. Delaying removal once this growth is visible can significantly reduce the potential fruit yield. Although the threat of severe freezing temperatures below 20°F (-6°C) must have passed, keep the removed mulch close by for re-covering if a late frost is predicted.
Step-by-Step Uncovering Process
The process of removing the winter cover should be gradual to avoid shocking the plants with sudden exposure to cold nights and bright sun. Initial removal involves gently raking the majority of the thick straw layer off the strawberry rows and into the pathways between them. This exposes the crowns to light and allows the soil to warm, which encourages vigorous spring growth.
A thin layer of straw, approximately one to two inches deep, should be left over the plants. This residual layer provides a temporary buffer against unexpected late spring frosts and helps prevent sun scald. This remaining straw also suppresses weed growth and keeps developing berries clean later in the season. Once the threat of frost is reliably over, this final thin layer can be gradually thinned or pushed entirely into the rows.
Immediate Spring Maintenance
Once the plants are uncovered, immediate maintenance tasks ensure a healthy start. Check the rows for any crowns that may have been pushed up, or heaved, by freeze-thaw activity. Heaved crowns should be carefully pushed back down into the soil so the roots are fully covered and in contact with the ground. Removing old, dead, and ragged foliage from the previous year is beneficial, as this debris can harbor disease and pests. A thorough weeding of the strawberry bed is best done now, before the plants fill in.
If the soil appears dry following the long winter under the mulch, watering the bed will help re-establish good soil moisture. Spring fertilization is generally needed for everbearing and day-neutral varieties, using a balanced fertilizer that is not overly high in nitrogen. June-bearing varieties, however, typically receive their main fertilization boost immediately after the harvest period.