When to Apply Winter Protection to Strawberry Fields

As winter approaches, growers find themselves asking when they should be covering their strawberries with straw for the winter. This is always a tough question. The timing of mulch application can greatly affect the plants ability to survive winter and can result in significant yield losses if applied at the incorrect time.

The guide to Commercial Strawberry Production on the Prairies indicates that straw is usually applied in late fall after several frosts but before air temperature drops to -6.7°C. This usually occurs between late October and Early November. Research at the University of Illinois determined the best soil temperature to apply straw mulch to the plants was 4 to 5 °C (at the 4 to 5 inch soil depth). Important to remember that plants need to be dormant before mulch application. Growers can use soil temperature testing combined with their own observations and guide recommendations to help them determine when to apply straw to their strawberries.

Adding mulch to protect strawberry fields in the winter 

Wheat or rye straw mulch should be applied 4-6 inches thick, which will settle down to 2-3. This works out to 2-3 tons per acre which is approximately 120 small bales or 12 round bales per acre required. A loose and fluffy covering of straw mulch will provide a good insulation layer. It is preferred that straw sticks up somewhat to help trap snow, as opposed to laying flat.