Raspberry

Raspberry is a perennial plant which bears biennial stems ("canes") from the perennial root system. In its first year, a new stem grows vigorously to its full height of up to 2.5 m, unbranched, and bearing large pinnate leaves with five or seven leaflets; normally it does not produce any flowers. In its second year, the stem does not grow taller, but produces several side shoots, which bear smaller leaves with three or five leaflets. The flowers are produced in late spring on short racemes on the tips of these side shoots, each flower about 1cm (½in) diameter with five white petals. The fruit is red, edible, sweet but tart-flavoured, produced in summer or early autumn; in botanical terminology, it is not a berry at all, but an aggregate fruit of numerous drupelets around a central core. The drupelets separate from the core when picked, leaving a hollow fruit, whereas in blackberry the drupelets stay attached to the core.

Location
A sheltered spot is required as shoots can be damaged by strong winds. Full sun is ideal, but raspberries will tolerate partial shade.

Soil
Raspberries require a pH of around 5.6 - 6.2, not too heavy and rich in organic matter. The primary concern, however, is waterlogging. Raspberries will die quickly if their roots stand in wet, airless earth for long periods.

Preparation
One month before planting; dig a trench 45cm (18in) wide and 23cm (9in) deep. Remove all weeds. Add a bucketful of compost or rotted manure every 1m (3ft) and spread across the bottom of the trench. Fill the trench back in and apply growmore

Planting
Dig into the site of the re-filled trench to 7-8cm (3in) deep and 30-45cm (12-18in) wide. Fan out the roots of the raspberry canes and place in the bottom of the trench with them spread evenly across the floor. Replace the soil to the original level and consolidate by gentle treading. If possible; cut back the stem to a bud 30cm (12in) above the soil level. Water in place thoroughly.

Support
Summer fruiting varieties will need support. There are many configurations of support system to choose from including wire, string or chain strung between supporting poles to wire the canes onto. Consider the amount of space available and the expected height of your crops and create a system of support onto-which the canes can be tied at spacings of approximately 30cm (12in) starting from 75cm (2½ft) from the ground.

Seasonal care
Raspberries are a thirsty crop. Water regularly during the first season if the weather is dry and ensure the soil is moist when the fruit is swelling.

Keep weeds at bay by hoeing regularly. Avoid damaging the roots growing near the surface by hoeing too deeply.

Apply a general fertiliser around March and apply a mulch of well-rotted manure or compost to keep the soil cool and moist and to suppress weeds.

Summer fruiting
In the first spring, cut the original cane down to near ground level once the new growth appears.
 * New canes

Remove any flowers which may appear on the canes in the first summer after planting.

Immediately after harvesting cut down all the canes which have fruited, retaining the best 6-9 young, unfruited canes and tie to wires 7-10cm (3-4in) apart.
 * Established canes

In February cut back tall growth to 15cm (6in) above the top wire.

Autumn fruiting
In February cut down all canes to just above ground level. Tie new canes to wires with soft twine as they grow in the spring.

Harvesting
Pick fruits when they are fully coloured, but still firm. Pull each raspberry away from the stem gently, leaving the plug and stalk behind. Avoid picking wet fruit as this will go mouldy quickly.

Preserving
Eat or freeze picked fruit as soon as possible. Small, slightly unripe fruits are the best for freezing.