This week Iowa State University Extension garden experts have answers to questions about growing strawberries in a home garden. Whether questions come from gardeners planning their first strawberry bed or maintaining an established bed, extension horticulturalists answer questions using the most current research. Gardeners with additional questions can contact the experts by emailing or calling the ISU Extension horticulture hotline at firstname.lastname@example.org or 515-294-3108.
Home gardeners can choose from three types of strawberries. June-bearers are the most widely planted type of strawberry. They produce one crop per year, the majority of fruit ripening in June. A second type of strawberry is the everbearing strawberry. Everbearing varieties typically produce fruit in June and late summer/early fall with little flowering or fruiting in the intervening weeks. Day-neutral varieties are the third type of strawberry. Day-neutral varieties flower and fruit throughout the growing season if temperatures are moderate. Flower and fruit production stop during hot weather.
Suggested June-bearing strawberry varieties for Iowa include "Earliglow," "Allstar," "Honeoye," "Surecrop," "Redchief," "Jewel" and "Kent." "Ozark Beauty" and "Ogallala" are good everbearing varieties. "Tristar" and "Tribute" are the best performing day-neutral varieties.
Purchase plants from a reliable garden center or mail-order nursery. Plants from an old planting may be disease infested. Plants purchased from reputable garden centers and mail-order nurseries should be disease-free.
If planting must be delayed after purchase, place moist material, such as wood shavings or sphagnum moss, around the plant’s roots and place the plants in a plastic bag. Store the plants in the refrigerator at 32 to 40 degrees Fahrenheit. The strawberries can be safely stored in the refrigerator for one to two weeks.
When selecting a planting site, choose an area that receives full sun and has a well-drained soil. Planting sites should receive at least six hours of direct sunlight per day. Leaf and root diseases are often problems in poorly drained, wet soils. Do not plant in areas that are heavily infested with perennial weeds. Perennial weeds, such as quackgrass, are extremely difficult to control in a strawberry planting. Also, avoid sites where strawberries, tomatoes, potatoes and peppers have been grown within the last two years to prevent possible root disease problems.
When ready to plant, trim off the older leaves, place the roots of the plants 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.
The type of strawberry determines plant spacing. June-bearing strawberries should be planted 18 to 24 inches apart in rows spaced 4 feet apart. Runners will develop and root freely to form a matted row about 2 feet wide. Everbearing and day-neutral strawberries are typically planted in beds consisting of two or three rows. Space rows 1 foot apart. Plants are spaced 1 foot apart within the rows. A 2-foot-wide path should separate the beds. Any runners that develop on everbearing and day-neutral strawberries should be removed and the plants maintained as large, single plants.
Immediately after planting, water the strawberry plants and apply a starter fertilizer solution to aid establishment. A starter fertilizer solution can be prepared by dissolving one or two tablespoons of an all-purpose garden fertilizer, such as 10-10-10, in one gallon of water. Apply one to two cups to each plant. A starter fertilizer solution can also be prepared using a water soluble fertilizer. Follow label directions when preparing the solution.
During the first growing season, all the blossoms should be removed from June-bearing strawberries. If the flowers are allowed to develop into berries, their development will reduce plant growth, runner production and the size of next year’s crop. Check the strawberry plants once a week and remove the blossoms by pinching or cutting. Flower production on June-bearing strawberries should stop by early July.
With everbearing and day-neutral strawberries, remove all blossoms until early July. Any flowers that bloom after this period may be allowed to develop into fruit. The first berries should ripen in August and continue until frost.