Allow two or three hard frosts to occur in the autumn to enable the strawberry plants to harden and acclimate to the cold before you mulch them.
Cover the plants with about 6 inches of straw after the third autumn frost. Ensure that you place the straw in a thick and even layer over the entire row of strawberry plants.
Pull back the mulch in the spring immediately after the plants begin growing again. Move the mulch so it covers the soil between the strawberries. The mulch will prevent weed growth during the upcoming growing season.
Replace the mulch to recover the strawberry plants if you expect a spring frost. Leave the mulch in place over the strawberries again only long enough to protect them from the frost and then pull it back again.