Fall & Winter Care of Strawberries
September is the time to ensure a good harvest from your strawberry planting next year. Strawberry flower buds begin to form in late summer, making this an important time of year to maintain good moisture levels in your strawberry bed. Plants generally required 1 ½- 2 inches or more of water each week depending on soil type and weather conditions. Apply enough water to wet the soil to a depth of 6-8 inches.
Ground plantings. Renovation of the planting should have been done in late June after harvest, but additional thinning is required in late summer. Strive for a spacing of five to seven plants per square foot by mid-October for optimum fruit production next year.
Which plants should be removed when thinning? The number of leaves on a daughter plant in fall is a good indication of the plant’s vigor and fruiting potential. More leaves in fall equals more fruit production in spring. So remove small and weak plants. Also remove any new runners or daughter plants that have not rooted down. These will not have enough time to become established before winter or initiate flower bud development. Removing them will redirect the plant’s energy into the remaining flower buds.
Cultivate, or hoe, carefully around the remaining plants to remove weeds without damaging the strawberry root system.
Strawberry plantings must be mulched for winter protection to produce consistently in Nebraska. Mulching prevents or reduces winter damage to the strawberry crown and flower buds. Most unprotected strawberry cultivars are injured at 15°F. Plant vigor, moisture conservation, weed control and improved fruit quality are benefits from mulching that continues through the summer.
Apply loose mulch to a depth of four inches in late November or early December after the soil has frozen to a depth of 1/2 inch, or the temperature has dropped to the 20s. Do not apply the mulch too early in the fall as it can delay hardening off, making plants more susceptible to winter injury, and increasing crown rot. Suitable mulches include wood chips, pine straw, newspapers, coarse sawdust, straw, clean hay or any loose mulch that will not compact heavily.
The mulch should remain on the strawberry plants until new growth begins, about mid-April. Blooming can be delayed by allowing the mulch layer to stay on the plants, but waiting too long for removal will reduce yield.
Row covers are an effective alternative to mulch. Unlike straw mulches, light penetrates the row cover material, increasing the number of blossoms formed by the strawberry plants, and consequently, the overall yield. One disadvantage to floating row covers is that they accelerate flower development. Be prepared to protect blossoms from late frost.
As early spring flowers begin to bloom, remove the row covers or mulch to allow for pollination, but recover the plants at night when frost is predicted. Be sure to remove only enough mulch to expose the leaves. Place this excess mulch in the walkways between the plant rows. Partial removal of the mulch allows for plant development but delays blooming by keeping the soil cooler and slowing plant growth.
Container plantings. Because plants growing in a pyramid, barrel or strawberry pot are elevated above ground level, and therefore are highly exposed to cold winter temperatures, additional winter damage can be expected to roots, crowns, and fruit buds. Consequently, care must be taken to provide adequate winter protection.
- Pyramids should be mulched with 6-8 inches of straw after the soil is frozen.
- Ideally, strawberry barrels should be moved to an unheated garage for the winter. If the barrel cannot be moved, protect plants with a burlap covering. For especially cold winters, enclose straw in the burlap for added insulation. However, even with careful mulching, some plant jury can be expected during severe winters.
- Strawberry pots should be moved to an unheated garage for the winter.
Providing adequate winter protection for your strawberry planting is an important step that will aid in better fruit production the following year.