How to grow raspberry
Overview
Raspberry (Rubus idaeus) is a deciduous fruiting shrub in the Rosaceae family, grown for its sweet-tart berries. It produces fruit on biennial canes (primocanes and floricanes) and requires a support system like a trellis or fence. The plant is cold-hardy but struggles in prolonged heat, making it best suited to cooler climates.
Varieties
- Chilcotin — A classic red raspberry with large, firm berries and good flavour; widely grown in cool and temperate zones.
- Willamette — Early-season, dark red berry with excellent disease resistance; popular in NZ and southern Australia.
- Autumn Bliss — Primocane-bearing (everbearing) variety that fruits in autumn; ideal for extending harvest in temperate climates.
- Nootka — A vigorous, high-yielding red raspberry with good heat tolerance; suited to Mediterranean zones.
Soil Preparation
Raspberries prefer well-drained, loamy soil with pH 6.0–6.5. Before planting, incorporate 2–3 kg/m² of well-rotted manure or compost and a handful of blood and bone. Ensure drainage is excellent; if clay, plant in raised beds or mounds. Avoid soil that stays wet in winter.
Growing Guide
Plant raspberries in full sun in well-drained, slightly acidic soil (pH 6.0–6.5). Space canes 50–60 cm apart in rows 1.5–2 m apart, with a trellis or wire support. Set crowns at soil level and water deeply after planting. Avoid heavy clay or waterlogged sites; raised beds help. In hot weather, provide afternoon shade or mulch to keep roots cool.
Care
Feed raspberries with a balanced fertiliser (e.g., 10-10-10) in early spring and again after harvest. Prune out spent floricanes (fruited canes) at ground level after harvest; tie new primocanes to the trellis. Mulch annually with straw or wood chips to 5–10 cm deep, keeping it off the canes.
Companion Planting
Plant raspberries near garlic, chives, or marigolds to deter aphids. Avoid planting near potatoes, tomatoes, or eggplants (Solanaceae) as they share verticillium wilt and other soil-borne diseases. Also keep away from blackberries to prevent cross-contamination of cane diseases.
Common Pests & Risks
Common pests include aphids (spread raspberry mosaic virus), raspberry cane borer (small holes in canes), and birds (netting essential). Diseases: cane blight (dark lesions on canes) and rust (orange spots on leaves). Control with clean pruning, removal of infected canes, and copper spray in winter. Bird netting over fruiting canes is critical.
Harvesting
Harvest raspberries when they are fully coloured (deep red for red varieties) and release easily from the receptacle with a gentle tug. Pick every 2–3 days in peak season, handling berries gently to avoid bruising. Harvest in the morning when fruit is cool and firm for best storage.
In the Kitchen
Raspberries are best eaten fresh within 2–3 days of harvest, or frozen for later use. They make excellent jams, sauces, and desserts (e.g., raspberry coulis, crumbles). Store unwashed in a single layer in the fridge; wash just before use.
Troubleshooting
Yellow leaves: often caused by iron deficiency in alkaline soil; apply iron chelate. Brown leaf edges: heat stress or sunburn; provide afternoon shade or mulch. Canes dying back: cane blight or borer; prune out infected canes below the lesion. Small, seedy fruit: insufficient water during ripening; keep soil evenly moist. Fruit not setting: poor pollination or cold damage; plant in a sheltered spot.