April is the best time to plant strawberries in Iowa, according to horticulturists with Iowa State University Extension and Outreach. A late freeze or frost could damage yields, and temperatures of 32-degrees may damage flowers. Apply fertilizer into the top 6 to 8 inches of soil before planting. If removing strawberry plants from storage, trim off older leaves and place roots in water for an hour before planting. It is recommended to set each plant in the ground sot the crown of the plant is even with the soil surface. After planting, immediately water the plants and apply a starter fertilizer.