Depending on the variety grown, raspberries can be harvested from early summer through fall. Once you decide on a variety suited to your zone, select a cultivar designed to bear fruit when you want berries. Since viral diseases are the number one problem for raspberries, select plants from a reputable nursery that are disease resistant and certified virus-free (virus indexed). Raspberries are self-fertile so you can get by with one plant to get a full crop of berries. Expect to pick your first crop anywhere from 8 months to 2 years after planting depending on the variety. Mature plants can produce from 4 to 6 pounds of berries per year.
Select a site with full sun and soil high in organic matter. Raspberries prefer acidic soil with a pH of 5.5 to 6.5. Avoid low areas prone to frost or standing water and site where berries or plants from the tomato family have been grown before. Wild raspberries can harbor viral disease and should be located no closer than 600 feet from the site or removed altogether.
Plants should be set into prepared holes at least 2 inches deeper than grown in at the nursery. Space plants at 3 feet intervals in rows and space rows at least 7 feet apart. If necessary, erect cane supports before setting plants. Keep the row between plants free from weeds by planting and mowing grass or heavy mulching.
Care & Maintenance:
Raspberries canes can be supported with a trellis or wire strung along posts in the ground. When and how to prune your plants will depend on the variety you're growing. Fall bearing raspberries are generally cut to the ground after harvest. Summer bearing plants are pruned twice per year, once after harvest, and again in the winter to thin canes and remove dead growth. Black raspberries need pruning three times per year-once when canes reach three feet tall (pinched back), once after harvest and again in the winter. Keep raspberries adequately watered from the time flowers form through the harvest season.
Harvesting & Storage:
Raspberries should be picked when they are thoroughly ripe. When berries are ready for harvesting, they will feel soft and separate easily from their core. Handle them with care as they are easily crushed. Pick them early in the morning while it's still cool. Berries will ripen unevenly so check your patch every other day to prevent berries from becoming over-ripe. Raspberries are extremely perishable. They will keep for only 1 day in the refrigerator and just 3 or 4 days when kept at slightly colder temperatures (31 to 32 F)
By Ellen Brown