Gordon Johnson, Extension Ag Agent, Kent Co.; gcjohn@udel.edu
Annual plasticulture strawberries should be scheduled for planting the first week in September. Research has shown considerable yield reductions each week that planting is delayed in the month of September. Plantings after September 15th risk much lower yields. If late planting cannot be avoided due to plant availability, labor issues, or other reasons, plan to apply floating row covers earlier in the fall to gain some additional growth. Another option for late plantings is to install vented clear plastic row covers supported by wire hoops over each bed to gain fall growth. These are then covered by floating row covers for winter, forming a double layer.
One main goal is to get the strawberry plants to regrow quickly after transplanting and irrigation is critical for this establishment period. Drip irrigation should be run ahead of planting to increase soil moisture to field capacity in beds. Overhead irrigation will be necessary if planting bare root plants and should be run for several days during daylight hours until new roots have been formed. Most growers are using rooted plug plants. Water plug plant trays to saturation just prior to setting. Ideally, water should be applied in the planting hole at transplanting. Overhead irrigation will also help the establishment of plug plants, especially in light textured soils where the drip irrigation system cannot uniformly water the whole bed.
Plant both bare root and plug plants so that the crown is at soil level. Planting too deep will risk soil getting into the crown and increases the potential for crown rot. Shallow planting will cause roots to dry out and plants will dessicate. Avoid planting in the middle of the day when the temperature beneath the plastic is at the maximum. Strawberry roots are very sensitive to high temperatures. Overhead irrigation can help to reduce plastic temperature and the lower the soil temperature.