How to grow your own raspberries - FreshFruitPortal.com

How to grow your own raspberries

Agronotips Agronotips - Conventional Agriculture More News Top Stories
How to grow your own raspberries
The content of this article was prepared by the U.K's Royal Horticultural Society 

Grow

Grow

Watering, feeding and mulching

Keep raspberries well watered in dry spells, but take care not to overwater. Avoiding drought stress is especially important during fruit set and development. Apply water preferably at ground level – a drip irrigation systems or leaky hose is ideal. Keeping the foliage, flowers and developing fruits dry helps to reduce the risk of fungal diseases.

In early spring, feed with a high potassium general fertiliser, such as Vitax Q4. Scatter one and a half handfuls per square metre/yard around the base. If growth is weak, apply sulphate of ammonia at 30g (1oz) per square metre/yard or dried poultry manure pellets at 90g (3oz) per square metre/yard. Then add a mulch of garden compost or well-rotted manure to deter weeds and help hold moisture in the soil.

When growing in a container, water and feed throughout the growing season – keep the compost moist and feed with a liquid general-purpose fertiliser on a monthly basis. In hard water areas, try to use harvested rainwater.

Propagation

Lift healthy suckers that appear between the rows and replant in a new spot. You can also divide large clumps. Only propagate from newly planted certified stock, as raspberries are prone to number of diseases and viruses. 

Pruning

Regular annual pruning will result in healthier plants and better quality crops. Summer and autumn raspberries are pruned in different ways.

Pruning and training summer-fruiting raspberries

Summer-fruiting raspberries (floricanes) produce flowers and fruit on one-year-old canes (the previous season’s growth).

  • In early summer, pull up suckers between the rows.
  • After harvesting in summer, cut back fruited canes to ground level – do not leave old stubs.
  • Select the strongest young canes that have grown during the current season, around six to eight per plant, and tie them in, 8–10cm (3–4in) apart, along the horizontal wire supports. These will fruit the following summer.
  • Cut the remaining (excess) young stems to ground level.
  • Loop longer canes over the top wire and tie them in. Then, in February, trim the long canes to a bud about 10cm (4in) above the top wire.

Pruning autumn-fruiting raspberries

Autumn-fruiting raspberries (primocanes) produce flowers and fruit on the current season’s growth.

  • Cut back all the old, fruited canes to ground level in February. New canes will start growing in spring, which will bear fruit later in the year.
  • Reduce the number of canes slightly in summer if they are very overcrowded. Thin to around 10cm (4in) apart.
  • During summer, remove any suckers growing away from the rows.

Pruning autumn raspberries for double cropping

Double cropping is useful if you don’t have space to grow summer-fruiting raspberries as well. The combined summer and autumn crop is at least five per cent larger than an autumn crop alone.

  • Start double-cropping only once the canes are well established and growing strongly. Cultivars such as ‘Joan J’, ‘Autumn Treasure’ and ‘Himbo Top’ are particularly suitable.
  • Instead of pruning all the previous season’s canes to ground level in February, select six to eight of the strongest stems per 1m (3ft) of row, and prune off the upper fruited part to leave the stems around 1m (3ft) tall. Prune the rest of the canes to ground level as normal.
  • The half-pruned canes will produce a modest, but valuable earlier crop. They should then be cut down to ground level straight after they finish fruiting the following summer.

Plant

How to choose raspberries

There are two main types of raspberries – summer-fruiting (floricanes) and autumn-fruiting (primocanes). Summer raspberries make larger, more vigorous plants that fruit from early summer, while autumn raspberries are generally smaller plants that crop from late August to October. They grow in slightly different ways, so need training and pruning differently too.

Raspberries are available as either bare-root plants (without soil around the roots) or in containers. Bare-root plants, or canes, are mainly sold by specialist fruit nurseries by mail order, while containerised plants are sold in garden centres too. Bare-root plants are only available during the dormant season, from autumn to early spring, while raspberries in pots are often available for a longer period.

There is a huge range of varieties to choose from, for early-, mid- and late-season crops. If you grow a selection, you can harvest berries from mid-summer to mid-autumn. Different varieties also offer a choice of plant sizes, and fruits of various sizes, flavours and even the colours – yellow-fruited raspberries as well as various shades of red.

Smaller cultivars such as ‘Glen Fyne’ and dwarf ‘Ruby Beauty’ are good choices for growing in containers.
When choosing varieties, look in particular for those with an RHS Award of Garden Merit (AGM), which shows they performed well in trials, so are an excellent choice. See our list of AGM fruit and veg.

Where to plant raspberries

Raspberries thrive in moisture-retentive, fertile, slightly acidic soil (ideally pH 6.5–6.7), which is well-drained and weed free. They dislike soggy soil and shallow chalky soil.  For best results, plant in a sunny position. They will tolerate light shade, but may produce a smaller crop. Ideally, position your rows running north to south, so the plants don’t shade each other. Avoid planting in very windy sites, as the flowers are self-fertile and pollinated by insects. Also, the fruiting side-branches of some cultivars are very long and may break in strong winds.

You can grow smaller varieties in large containers.

When and how to plant raspberries

Raspberries can be planted at any time during the dormant season, between November and March, providing the soil is not frozen or waterlogged. However, autumn is the best time to plant. 

Before planting, clear the site of perennial weeds, as these are difficult to control once raspberries are established. Dig in lots of well-rotted manure – at least a bucketful per square metre/yard – and add a general fertiliser or blood, fish and bonemeal.

Raspberry canes need supports, which are best put in place at planting time – there are several different methods to choose from, depending on how much space you have and which type of raspberries you are growing. See How to support raspberries, below.

Space the plants 45–60cm (18in–2ft) apart, and space the rows 1.8m (6ft) apart. If the soil is heavy and damp, make a 7cm (3in) high ridge and plant into it, or plant in raised beds.Avoid deep planting – the first roots should be no more than 5cm (2in) below the soil level. Use the soil mark on the stem as a guide. After planting, cover the soil with a 7.5cm (3in) thick mulch of bulky organic matter, such as garden compost. Avoid alkaline mushroom compost or overly rich farmyard manure, which can burn the new shoots.

Cut the stems, or canes, down to 25cm (10in) tall after planting. However, don’t prune summer-fruiting raspberries bought as one-year-old canes (long canes), otherwise you will lose the fruit for that season.

How to support raspberries

Raspberries are usually planted in rows and supported by a system of posts and horizontal wires. But if you don’t have room for this, you can grow just a couple of plants supported by a single post, or one plant in a container (see below) supported by bamboo canes. The supports should be put in place at planting time.

Single fence

This system of posts and horizontal wires is ideal for summer-fruiting raspberries in small gardens:

  • Install tall, sturdy posts at 3.6m (12t) intervals in the middle of the row. Ideally the posts should be 2.5m (8ft) tall and 75mm (3in) in diameter, inserted to a depth of 75cm (30in).
  • Stretch 12 gauge (3.5mm) galvanized wire between the posts, at 60cm (2ft) vertical intervals.
  • Plant the summer-fruiting raspberries and tie in the canes along one side of the wires.
  • Keep fruiting canes on one side and young new canes for fruiting next year to the other side of the wires as the season progresses. This way, the fruited canes can easily be pruned out and the young canes will be separate along the other side of the wire.

Single or double fence with parallel wires

This system is well suited to autumn-fruiting raspberries, as well as for summer-fruiting raspberries in a small space, where it helps to increase the crop. Tying in the canes is not necessary as they are kept fenced in by the parallel wires. However, picking is a little more difficult, and there is a greater chance of fungal problems in the more crowded conditions.

  • Install tall, sturdy posts at 3.6m (12ft) intervals in the middle of the row. Ideally the posts should be 2.5m (8ft) tall and 75mm (3in) in diameter, inserted to a depth of 75cm (30in).
  • Attach two short horizontal lengths of timber to each post, one at the top and one 60cm (2ft) below.
  • Stretch 12 gauge (3.5mm) galvanized wire in parallel lines along the ends of the horizontal lengths of timber to create two parallel lengths of wire along the fence.
  • Stretch thin wire or twine between the parallel wires as cross ties, every 60cm (2ft) along.
  • The canes do not need tying in, as they will be supported by the parallel wires and cross ties.

For a double fence, insert posts (as above) along each side of the row rather than in the middle, then fix two sets of horizontal wire to them, at 60cm (2ft) vertical intervals. Stretch thin wire or twine between the parallel wires as cross ties, every 60cm (2ft) along.

Single post

This system is ideal for very small gardens:

  • Install a tall, sturdy post, 2.5m (8ft) tall and 75mm (3in) in diameter, inserting it into the ground to a depth of 75cm (30in).
  • Plant two or three raspberry plants around the base of the post and tie the stems to it with twine. 

Planting raspberries in containers

Raspberries, especially smaller varieties, can grow well in large pots in a sunny, sheltered spot:

  • Choose a container at least 38cm (15in) wide and fill with 80 per cent multi-purpose compost and, to add weight for stability, 20 per cent loam-based potting compost.
  • Plant a single raspberry plant in the centre, insert bamboo canes for support and tie in the stems.

Harvesting

Harvesting

The first summer raspberries are ready for harvesting in early summer, while autumn raspberries won’t mature until late summer, often continuing until the first frosts.

Harvest regularly, to get fruits at the peak of ripeness, when richly coloured, plump and easy to pull off. Pick on a dry day, so the berries aren’t wet.

Eat them fresh, freeze them or make into preserves.

Subscribe to our newsletter