Select a planting site with good soil drainage and all-day exposure to direct sun. Avoid poorly drained, shaded areas. Strawberry plantings established on wet sites are doomed to failure. Good weed control is by far the most important sanitation measure for strawberry production. Weeds compete strongly with shallow-rooted strawberry plants and interfere with good runner-plant production. Weeds also harbor many insect and mite pests and prevent rapid drying after rains, which promotes fruit rots. A good straw mulch in place before the fruit begins to ripen will help reduce fruit rots by keeping the berries from touching or being splashed with soil. Renovate beds immediately after harvest to reduce pest problems. Rake and destroy cut-off leaves and stems after renovation. Select and use varieties with resistance to leaf diseases, Verticillium wilt and red stele (see Table 14). For more information on varietal susceptibility, see Ohio State University Extension Bulletin 436, Ohio Strawberry Manual. To reduce populations of sap beetles, remove overripe, diseased and damaged fruit at regular intervals. When old plantings are replaced by new ones, select a different growing site to prevent buildup of soilborne diseases, insects and weeds.
Mite damage appears as distorted and discolored leaves and stunted fruits. Silken webs may also be found on the lower surface of the leaves. The two species of mites found on strawberries are the two-spotted spider mite, which is usually light gray with two dark spots on its back, and the cyclamen mite, which is so tiny that it is scarcely visible to the naked eye. Both mites suck sap from the foliage, and heavy populations can cause serious damage to strawberry plantings. Life cycles of both species are quite short during the summer, and under ideal weather conditions, they can build up rapidly if left uncontrolled.
When the two-spotted spider mite is a problem, growers should use a miticide such as Kelthane (dicofol) (Table 15). Hot, dry weather favors rapid development of the two-spotted spider mite, particularly in July and August. Miticide should be applied if mite populations reach five per leaflet. For best spider mite control, apply two sprays of miticide spaced 7 to 10 days apart in the spring or spaced 5 to 7 days apart in the summer.
Populations of cyclamen mite usually begin to increase in late May when blossoming starts, and peak in early July during fruiting. A sharp decline in cyclamen mite populations generally occurs during July and August. Observations for cyclamen mite probably are best made before blossoms appear. Control measures should be applied at the first sign of an infestation. For best cyclamen mite control, apply Thiodan (endosulfan) 1 to 2 days before bloom, and again 10 to 14 days later.