How to grow raspberries

Raspberries are available as either bare-root plants (without soil around the roots) or in containers. Bare-root plants (or canes) are mainly available from fruit nurseries and larger online plant retailers by mail order, while containerised plants are available in garden centres too.

Bare-root plants are only sold during the dormant season, from autumn to early spring – they tend to be cheaper and sold in bundles of five or more, so ideal if you want to plant a row. Raspberries in pots are often available for a longer period, but may be more expensive. For the widest choice of varieties, go to fruit nurseries and online fruit specialists. Take care to buy plants that are certified virus-free, as raspberries are prone to virus infections, which reduce their vigour and cropping.  

Smaller raspberry 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 peat-free multi-purpose compost and, to add weight for stability, 20 per cent peat-free soil-based potting compost

• Plant a single raspberry in the centre, at the same level it was previously growing

• Insert bamboo canes for support and tie in the stems

Raspberries need plenty of moisture to sustain their lush foliage and swell their fruit, so keep them well watered in dry spells, especially when flowering and fruiting. It’s best to water at ground level – a drip irrigation system or leaky hose is ideal. Keeping the foliage, flowers and fruit dry helps to reduce the risk of fungal diseases.
 
When growing raspberries in a container, water throughout the growing season to keep the compost consistently moist. In hard water areas, use rainwater whenever possible.

Apply a thick layer of mulch, such as garden compost, around raspberry plants after feeding in early spring (see below). This helps to hold moisture in the soil and deter weeds. Leave a gap around the base of the stems to avoid rotting.

In early spring, feed with a high potassium general fertiliser, such as Vitax Q4 or fish, blood and bonemeal. Scatter one and a half handfuls per square metre/yard around the base of plants. 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. 
 
When growing raspberries in a container, feed with a liquid general-purpose fertiliser on a monthly basis throughout the growing season.

Raspberries are usually planted in rows and supported by a system of posts and horizontal wires – the two main methods are outlined below. If you don’t have room for a row, you can just grow a couple of plants supported by a single post (see below), or one compact plant in a container supported by bamboo canes.

Single fence  

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

• Install a tall, sturdy post at each end of the row, plus extra posts at 3.6m (12ft) intervals if necessary. They should stand about 1.8m (6ft) tall

• Attach three lengths of strong galvanized wire horizontally between the posts, at 60cm (2ft) intervals

• Plant the summer-fruiting raspberries and tie in the stems along one side of the wires

• Keep all the fruiting stems on one side, and the young new stems for next year’s crop on the other side 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 ideal for autumn-fruiting raspberries, and for summer raspberries in a small space. Tying in individual canes isn’t necessary, as they are fenced in by parallel wires either side. However, harvesting is a little more tricky, and there is a greater chance of fungal problems due to more crowded conditions.

• Install a sturdy post at each end of the row – they should stand about 60cm (2ft) tall for autumn raspberries and 1.8m (6ft) for summer raspberries. Add extra posts at 3.6m (12ft) intervals if necessary

• Attach short lengths of timber horizontally to the top of each post, plus another 60cm (2ft) below on the taller posts for summer-fruiting raspberries

• Attach strong galvanized wire to the ends of the horizontal timbers to create parallel wires along each side

• You can also add thinner wire or twine between the parallel wires as cross ties, every 60cm (2ft) along the row

• Plant the raspberries in a row between the posts. The stems don’t 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 horizontal wires to the posts at the spacings described above. You can also add cross ties if you wish.

Single post

This system is ideal for very small spaces:

• Install a sturdy post that stands about 60cm (2ft) tall for autumn raspberries and 1.8m (6ft) for summer raspberries

• Plant two or three raspberry plants around the base of the post and tie the stems to it with twine.

It’s easy to make new plants from existing raspberries, to extend your row or start new ones. Simply dig up any healthy suckers that appear outside the row and replant in the new location. You can also divide large clumps.  
 
Only propagate from recently bought plants that are certified virus-free, as raspberries are prone to a number of diseases and viruses as they age, which would infect the new plants too, reducing their vigour and cropping potential.

Summer-fruiting raspberries (floricanes) produce fruit on one-year-old stems (the previous season’s growth). They should be pruned and trained straight after you finish harvesting the crop, as follows:  

• Cut all the old, woody, fruited stems right down to ground level

• Then select the strongest young green stems that have grown during the current season – around six to eight per plant – and tie them to your horizontal wires, spacing them 8–10cm (3–4in) apart. These will fruit the following summer

• Cut any other young stems to ground level

• If the young stems are taller than the top wire, loop them over and tie them in temporarily. Then in February, trim back these long canes to a bud about 10cm (4in) above the top wire

Autumn-fruiting raspberries (primocanes) produce their crop on the current season’s stems. They are easy to prune: 

• In February, cut back all the old, fruited stems to ground level. New ones will start growing in spring, which will bear fruit later in the year

• In early summer, thin out any very overcrowded clumps if necessary, removing weaker stems so the remainder are about 10cm (4in) apart

Double cropping is useful if you don’t have space to grow summer-fruiting raspberries as well. You’ll get a modest summer crop, and a slightly reduced autumn crop, but the combined harvest should be at least five per cent larger.  
 
To prune for a double crop:

• In February, instead of cutting all the stems to ground level, select six to eight of the strongest ones per 1m (3ft) of row, and prune off just the upper fruited part

• Cut all the other stems to ground level as normal

• After the half-pruned stems have fruited in summer, cut them down to ground level, leaving the current year’s stems to fruit in autumn

Use this method only on well-established plants that are growing strongly. Varieties such as ‘Joan J’ and Himbo Top are particularly suitable.

All raspberries will send up suckers, or new canes, in spring. Any that sprout up outside the intended growing area should be removed. If you want more plants, the suckers can be replanted in a more suitable spot, as long as your existing raspberry plants are young, healthy and virus-free.