The warm weather this spring may have tempted some gardeners to remove the mulch from their strawberry beds. However, a portion of the strawberry crop may be lost if the mulch is removed too early in the spring. Removal of the mulch plus a few days of unseasonably warm weather may encourage the plants to bloom before the danger of frost or freezing temperatures is past. Temperatures of 32 F or lower may severely damage or destroy open flowers. Damaged blossoms have a darkened center. Since the first flowers produce the largest berries, a late spring frost can drastically reduce yields.
To reduce the chances of frost or freeze damage, gardeners should leave the mulch on until the plants show signs of growth. Periodically examine the plants under the mulch during periods of warm weather in the spring. Remove the mulch from the strawberry plants when about 25% of the plants are showing new growth. New growth will be white or yellow in color. (In central Iowa, the winter mulch on strawberries is normally removed around April 20. The last frost typically occurs about May 5-10.) Rake the mulch to the center aisles between rows. If there is a threat of light frost later in the season during bloom, the mulch can be lightly raked back over the plants.
This article originally appeared in the March 25, 1992 issue, p. 35.