by Nancy Garrison, Former Urban Horticulture and Master GardenerProgram Coordinator with U.C. Cooperative Extension
Strawberries can be grown in the home garden and will provide a sweet tangy fruit high in vitamin C. There are two general classes of strawberries, the "day neutral" or as they are also called, "everbearers" and the "short-day" types. The day neutral types flower and produce fruit all year round; although, the bulk of the fruit will be from April through October. The short-day types produce when day lengths are shorter as in the fall through early spring. Pajaro, Seascape, Chandler and Tioga are short-day types, while Aptos, and Fern are day-neutral types. Day-neutral varieties can bear fruit about 3 months after planting, if favorable growing temperatures prevail. Varieties to choose from for best flavor are Aptos, Chandler, Seascape, Tioga, Fern, and Pajaro.
Factors Affecting Growth
Long days and warm temperatures favor the growth of leaves and runners, while short days and cool temperatures are necessary for flower formation in the short-day varieties. Strawberries will have more flavor when grown in areas where days are sunny and nights are cool. Strawberries that grow during cool temperatures have firmer fruit than those grown during warm humid weather. Temperatures of 70 to 80 F during the day and 60 to 65 F during the night result in a ripening period of about 30 days.
If planted in the ground, do so on raised beds that have not had members of the Solanaceae family (tomatoes, pepper, eggplants) grown in that location for at least 3 years. Amend soil with compost, well-composted or aged manure and fertilize with alfalfa meal or a vegetable food fertilizer following label recommendations for rate. After soil is amended, fertilized, and ready to plant, cover soil with a weed block material, preferably with drip underneath. Cut an "X" into material to plant through fabric. This will protect berries from most of the snails, slugs, earwigs, and sowbugs that like to munch on the berries when they are in contact with the soil, as well as minimizing berry rot.
Set the plants 8" to 14" apart in single rows on top of beds that are at least 5" to 6" high and 6" to 12" wide on top or in double rows that are 12" to 24". Space the beds at least 28" apart from center to center. Where no beds are used, set the plants 12" to 16" apart and allow about 28" between rows. Plant so that the upper part of the crown (the area between the roots and the leaf stems) is slightly above or level with the ground – never below grade. Set the roots downwards. Strawberry plants have shallow roots so they need moisture throughout the growing season. Drip irrigation is recommended so that moisture is kept away from fruit minimizing fruit rot. Keep soil moist but not soggy. Organic mulches tend to favor earwigs, sowbugs and snails and slugs which munch ripening berries, so may not be a wise choice.
A great way to grow strawberries, is to plant in narrow planter boxes that are approximately 6" to 8" deep by 5" to 7" wide by 18" to 4' long. Use fresh, not recycled potting mix mixing in additional fertilizer as directed on the fertilizer label. Thoroughly incorporate fertilizer into potting mix. Plant so crowns are not buried by time you water in. Keep moist but not soggy. Grow in full sun all day and expect luscious berries in 3 months. They are BEAUTIFUL ornamental plants, which will dazzle your visitors. They should be spaced 10" to 14" apart depending on level of fertilization and plant size. Pajaro variety produces the largest plants requiring the greater planting distance,
Prune off all runners that develop the first season so all the energy is focused into fruit production. If the plants are not sized up when flower production starts, remove first flush of flowers. If berry production or plants are less vigorous in subsequent years, you may want to put in new plants in fresh soil to get that incredible vigor you witnessed the first year. Commercially, they are usually treated as annuals even though they are, in fact, perennials.