Getting Strawberry Plants Ready for Winter

Strawberries are a great crop for the backyard garden or farm. They can be eaten fresh,  processed into jams and jellies, or frozen for later use. A small, raised bed does not take up a lot of space and can be very productive. Each plant may produce up to one quart of fruit when grown in a matted row system.

Reasons to Mulch

Strawberries should be mulched in the fall to protect plants from winter injury in West Virginia. If you grow strawberries in field conditions or in raised beds, plants must be prepared for winter to enable a successful harvest next spring. Mulching also helps control diseases and weed competition.

Winter can be tough on strawberries. Low temperatures and repeated freezing and thawing of the soil through the winter months can damage strawberry plants. Temperatures below 20 F may kill flower buds and injure the roots and crowns of plants that aren’t protected by mulch. Repeated freezing and thawing of the soil can heave plants out of the ground and cause severe damage or kill plants.

Allow Time for Plants to Acclimate to Cold Weather

Do not mulch too early. Allow the strawberry plants to harden or acclimate to cool fall temperatures before mulching the bed. Generally, the plant “flattens out” and the leaves turn light red/green when they have become dormant. Plants need time to adjust to cold weather and will gradually become more cold-resistant as fall progresses.

Hardened strawberry plants can withstand colder temperatures as winter progresses. Lack of hardening off may be a concern during an unseasonably warm fall. If a sudden drop in temperatures to below 20 F is in the forecast, plants should be mulched immediately or they may be severely damaged.

When to Mulch

In West Virginia, strawberries should be mulched for the winter around Thanksgiving. This is typically after the ground is frozen and we have nighttime temperatures near 20 F and soil temperatures are consistently below 40 F.

However, if temperatures stay abnormally warm, give plants another couple of weeks to become cold hardy or dormant before mulching.

Mulching plants helps to protect strawberries not only from low temperatures but also from heaving damage. This occurs from alternate freezing and thawing of the soil that heaves plants out of the ground. The roots become exposed and the plants die from lack of water.

Mulching Materials

Wheat straw or rye straw makes good mulch and is widely available in the Mountain State. The straw should be spread over the plants to a depth of 4 to 6 inches. Shake the slabs of straw apart so there are no large, compressed chunks.

Local garden centers, hardware stores and farms often sell square bales of straw for about $5 to $8 per bale. A bale should provide enough mulch for a 10-foot-long row of strawberries.

This straw mulch not only helps protect the plants throughout the winter but can also help avoid damage from late spring frosts by delaying blooms by a few days in the spring. Mulch should be removed gradually in the spring as plants begin new growth. Remove enough so that plant leaves can be seen.

Leave the mulch on as long as possible in spring to reduce the chances of crop damage from a late frost or freeze. Removing the mulch in March may encourage the plants to bloom before the danger of frost has passed. A temperature of 32 F or lower may severely damage or destroy open flowers.

Mulch Removal

Regularly examine the strawberry plants in the spring to determine when to remove the mulch. It is recommended to remove mulch when approximately 25% of the plants are producing new growth. Strawberry plants can produce up to three years with proper care and management. Good luck and happy gardening!

For more information contact:

J.J. Barrett, WVU Extension Agriculture and Natural Resources Agent-- Wood County, at 304-424-1960 or jj.barrett@mail.wvu.edu

References

Annie Klodd. “Cover Strawberries with Straw for the Winter”. University of Minnesota Extension. November, 2021.

Richard Jauron, Willy Klein. “Prepare Strawberries Plants for Winter”. Iowa State University Extension Yard and Garden. October, 2011.

Ward Upham. Winterizing Strawberry Plants. Kansas State Research and Extension Horticulture Newsletter. November, 2019.

Author: JJ Barrett, WVU Extension Agent – Wood County

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