AMES, Iowa — Strawberries are hardy, easy to grow and produce a good crop with moderate effort, making them well suited to home gardens. Early spring is the best time to plant strawberries in Iowa, but don’t rush to remove mulch. Gardeners with additional questions can contact the horticulturists with Iowa State University Extension and Outreach at firstname.lastname@example.org or 515-294-3108.
To reduce the chances of crop damage from a late frost or freeze, leave the mulch on as long as possible. Removing the mulch in late March may encourage the plants to bloom before the danger of frost is past. Temperatures of 32 degrees Fahrenheit 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.
To determine when to remove the mulch, periodically examine the strawberry plants in spring. Remove the mulch from the strawberry planting when approximately 25 percent 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 material to the aisles between rows. If there is a threat of a frost or freeze later in spring during bloom, lightly rake the mulch over the strawberry plants.
Established plantings of June-bearing strawberries should not be fertilized in spring. Spring fertilization stimulates foliar growth, produces softer berries and increases disease problems. Lush, vegetative growth may make picking difficult. Also, soft berries are more likely to be attacked by fruit rots. As a result, a spring fertilizer application may reduce fruit yield.
Fertilizer should be applied to June-bearing strawberries during the renovation process immediately after the last harvest of the season. Apply approximately 5 pounds of 10-10-10 or a similar analysis fertilizer per 100 feet of row.
Everbearing and day-neutral strawberries can be fertilized in early spring and again in early August. Apply 5 pounds of 10-10-10 or a similar analysis fertilizer per 100 feet of row.
Early spring (April) is the best time to plant strawberries in Iowa. Apply and incorporate the recommended type and amount of fertilizer (based on soil test results) into the top 6 to 8 inches of soil prior to planting. If the fertility level of the soil is unknown, apply and incorporate 1 pound of 10-10-10 or a similar analysis fertilizer per 100 square feet.
Remove the strawberry plants from storage when ready to plant. Trim off the older leaves, place the roots in water for an hour, then plant immediately. Set each plant in the ground so the crown of the plant is even with the soil surface.
Immediately after planting, water the strawberry plants and apply a starter fertilizer solution to aid establishment. Use a water soluble fertilizer following label directions or dissolve 2 or 3 tablespoons of a complete garden fertilizer, such as 5-10-5 or 10-10-10, in one gallon of water.