To reduce the chance of frost or freeze damage, gardeners should leave the winter mulch on strawberries for as long as possible. Removal of the mulch in March or early April may encourage the plants to bloom before the danger of frost is past. Temperatures of 32 F or lower may severely damage or destroy open flowers. Since the first flowers produce the largest berries, a late spring frost or freeze can drastically reduce yields. Leaving the mulch on through March and early April will delay or slow growth and reduce the risk of frost or freeze damage.
To determine when to remove the mulch, periodically examine the strawberry plants in spring. Remove the mulch from the strawberry planting when about 25% of the plants are producing new growth. New growth will be white or yellow in color. (If possible, the winter mulch on strawberries should remain until mid-April in central Iowa.) When removing the mulch, rake the straw to the aisles between rows. If there is a threat of a frost later in the season during bloom, the mulch can be lightly raked back over the strawberry plants.
This article originally appeared in the 3/12/2004 issue.