For raspberries, virus-indexed, tissue-cultured plants should be planted in the early spring. Raspberries should not be planted in poorly drained soils or after any of the verticillium-susceptible crops (tomatoes, potatoes, peppers, eggplant, strawberries). If available, use tissue-cultured blackberries as well; however, dormant canes may also be planted. In-row spacings (spaces between the plants) are as follows: red raspberries, 24 inches; black raspberries, 30 inches; purple raspberries, 36 inches; blackberries, 36 to 60 inches.
Between-row spacing should be no less than 8 feet, although the spacing depends on the size of the equipment that will be used to maintain the planting. Between rows, allow at least 4 feet more than the width of the widest implement to be used in the planting. Remove flower blossoms in the first year to encourage plant establishment.
See Getting Started for soil testing procedures prior to planting. If the soil is prepared properly before planting, only nitrogen is routinely necessary on an annual basis. The soil should be tested every 3 to 4 years after planting to determine the need for other nutrients. Apply no more than 5 pounds of 10-10-10 per 100 linear feet of row in the first year and no more than 10 pounds in subsequent years.
Do not overfertilize. If plants appear to be overly vigorous, reduce the amount of fertilization. Brambles benefit from irrigation, especially during fruit swell, which occurs during the week prior to ripening. Trickle irrigation is preferred for brambles because wetting the fruit with overhead irrigation can increase the incidence of disease. Plants generally require 2 inches of water per week, up to 4 inches during harvest.
Harvest and Postharvest Care
Brambles, like all small fruit crops, should be harvested in the morning after the dew has dried. This allows a minimum of field heat buildup in the fruit and will result in longer shelf life. Ripe berries will detach easily. They should be rolled off the plant, rather than squeezed or pulled, and put in half-pint containers. Larger containers cause the lower layers of berries to be crushed.
Raspberries are notorious for their poor shelf life. To maximize shelf life, maintain good disease control in the field and pick berries in the morning after the dew has dried but before field heat can build up in the berry. Do not allow overripe berries to remain on the canes. Refrigerate berries immediately. They can be kept for up to a week under these conditions. Blackberries should be handled similarly, although blackberry shelf life is several days longer than that of raspberries.