Raspberry is a perennial cane fruit grown for summer or fall berries. The roots live for 10 years or more and spread by suckers into a row, and a 20-foot planting keeps a household in fruit. Red raspberries are the hardiest; the gold ones are red raspberries without the pigment; black raspberries are a different species with a different habit.
Canes are biennial. They grow leaves the first year (primocanes) and fruit the second (floricanes), then die. Summer-bearing types fruit on second-year canes: cut out the spent canes right after harvest and thin the new ones to five or six per foot of row. Fall-bearing (everbearing) types fruit on the tips of first-year canes in late summer: the simplest regime is to mow the whole row to the ground in late winter and take one big fall crop. Train canes to a wire trellis or a post to keep them upright and let air through.
Plant bare-root canes in early spring, 18 to 24 inches apart in rows 6 to 8 feet apart, in rich, slightly acid soil that drains, in full sun; raspberries rot in wet ground. Water steadily while the fruit swells, mulch, and keep the row weeded. Pick when the berries pull free easily, every other day in season. Japanese beetles, cane borers and birds are the usual company; a net stops the birds. Deer browse the canes.
Cane Anthracnose
Small purple spots on young canes that enlarge into gray, sunken lesions with purple borders. Severe infections weaken canes and reduce fruit quality.
Prune and destroy infected canes. Improve air circulation by thinning. Apply lime sulfur during dormancy before bud break. Avoid overhead watering.
Botrytis (grey mould)
Grey fuzzy mould on petals and stems, worst in cool wet conditions.
Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.
Verticillium Wilt
Lower leaves yellow and wilt, often on one side of the plant, with brown streaking in the stem and crown tissue when cut open. Plants are stunted and decline over the season.
Remove and destroy affected plants. Avoid planting in soil that has grown infected tomatoes, peppers, or other susceptible crops. Rotate beds and improve drainage; there is no cure once a plant is infected.
Spotted Wing Drosophila
Drosophila suzukii →Soft, collapsing berries with small puncture marks; white larvae inside ripening or ripe fruit.
Harvest fruit promptly and frequently. Remove and dispose of overripe or fallen berries. Use fine-mesh netting or traps. Refrigerate harvested fruit immediately.
Japanese Beetle
Popillia japonica →Adults skeletonize leaves and devour petals and buds; aggregations escalate rapidly. Grubs destroy turf in late summer and fall.
Hand-pick adults in early morning into soapy water - beetles are sluggish when cool. Neem oil applied to foliage deters feeding but must be reapplied after rain. For grubs, apply milky spore (Bacillus popilliae) to turf - it takes 1–3 seasons to establish but provides long-term biological control. Beneficial nematodes (Heterorhabditis bacteriophora) applied in late August when grubs are young and near the surface offer faster results. Never use pheromone traps.