There are two kinds of raspberries: summer-fruiting varieties that produce fruit on the previous season’s shoots in summer, and the lighter-cropping autumn varieties that fruit on the current season’s growth from early autumn onwards. A few varieties fruit twice, in summer and in autumn.
Planning the crop
Choose a sunny, sheltered position. Raspberries need a moisture-retaining but well-drained and rich soil that is a little acidic. Dig a generous quantity of well-rotted manure or compost into the bed. This is essential if the soil is alkaline. Rake in a surface dressing of pelleted slow-release organic fertiliser. Raspberries are usually trellised. Provide three horizontal support wires, either between strong, well-embedded, free-standing posts or against a fence. Raspberries can also be planted singly on poles or metal star posts and tied in.
How many to grow- Raspberry plants are suckering shrubs that grow up to 2 m each season from shoots that emerge at ground level. A 3.5 m row will support 12 canes, which should eventually yield over 10 kg of berries in a season. Allow 12 plants per raspberry lover.
Chilliwack- Summer-fruiting variety; plump, sweet berries that hold well; almost thornless.
Heritage- Autumn-fruiting variety; heavy bearing; large red berries. Prune down to the ground in winter.
Williamette- Bears two crops, the first n summer, the second in autumn.
Golden-Autumn-fruiting variety; richly flavoured.
Raspberries are highly susceptible to virus diseases, and it is important to purchase one-year-old canes that have been certified disease-free. Only buy stock from a reputable nursery. Plant the canes from late autumn to early spring. If you have purchased bare-rooted canes, soak the roots in diluted sea weed liquid fertiliser for about half an hour before planting. This will give them a boost. If growing plants on a trellis, ridge up the soil on each row 25 cm wide and 10 cm high for good drainage. Set the raspberry canes in this, 45 cm apart, and mulch well with nitrogen-rich lucerne hay, keeping it away from the stems. Cover the roots with soil, and firm this down with your foot. Space rows 1.8 m apart. You can improve yields by applying 30 g of sulphate of potash per square metre as well as 30 g of Epsom salts dissolved in 4 litres of water per square metre.