How to grow raspberries

Thanks to John Harrison of Allotment & Gardens

Raspberries (Rubus ideaus) are a self fertile cane fruit which prefer a slightly acidic soil, which drains well. They are prone to root rot in waterlogged soil, and dislike really chalky soils. They do well in a sunny spot, but will tolerate partial shade.

There are two groups of raspberries: floricanes, which  fruit on canes grown the previous season  (These fruit in the Summer ) and primocanes which fruit on canes grown that year (These fruit in late Summer or Autumn).

Most varieties bear red fruit, but some are yellow, black or purple. All are deciduous.

Recommended Raspberry Varieties:

  • Glen Moy  – early Summer fruiting on virtually spine free canes
  • Glen Ample – mid Summer fruiting on virtually spine free canes; very heavy crops of large, deep red berries
  • Cascade – resistant to root rot so useful in areas where the soil is very wet
  • Tulameen –  mid Summer fruiting, on very tall canes that fruit more heavily and more accessibly if stopped at about 1m, to encourage branching
  • Polka – Autumn fruiting from late July to October. Very large deep red fruits. Good disease resistance
  • Fall Gold – Autumn fruiting golden variety which have very spiny canes.
  • Royalty – Summer fruiting variety with purple fruits and very spiny canes. Clump forming.

Raspberry Pests & Problems

See: Raspberry Pests & Problems

Growing Raspberries

Raspberries are best planted as leafless canes, usually cut back to about 30-40 cm, in Spring. All weeds should be removed prior to planting.

Raspberries thrive if given some well rotted manure or compost in the hole, and some Fish Blood and Bone sprinkled onto  the surface of the soil around them and raked in lightly. A mulch of old Autumn leaves or garden compost keeps them from drying out. Despite the long list of possible problems and diseases, raspberries are usually very straightforward and give a very worthwhile crop.

Summer fruiting varieties (floricanes) can grow very tall and need support. The traditional method is to fix two posts about 40-50 cm apart at one end of the row and two at the other, with wires fixed firmly between the two long sides to support the canes on both sides to stop them blowing over.

If you are only growing three or four canes, they can be spaced around one post and tied in with wire around the canes. Summer fruiting varieties  will not fruit in the first year they are planted, but will flower and fruit the following year. Once the fruit has been picked, these brown canes should be cut out at ground level. The green canes that will grow will flower the year after and so should be trained in between the wire supports.

Autumn fruiting varieties (primocanes) flower and fruit on the growth made earlier in the same year, and so will fruit the first year after being planted. These tend to be shorter than Summer fruiting varieties, and so do not usually need support.

They fruit on the growth made that year, and so each cane can be cut down to the ground in the Spring, ready to start again.

Both types benefit from Fish, Blood & Bone early in the Spring once the ground has thawed, and a top up mulch. Collecting up and disposing of fallen Autumn leaves will improve hygiene and reduce the chance of disease.

Raspberries spread by underground runners, which need to be removed by pulling up, to keep the fruiting canes in their planned area. Do not use weed killer on these shoots, as it will travel back to the main plant and may kill it.

Harvesting, Eating & Storing Raspberries

Raspberries should be harvested as they ripen. When picked, they leave the core of the fruit on the plant, and must be handled gently. Crops can be very prolific and so there are usually enough to eat with cream –look at the price of fresh raspberries in the shops! – as well as enough to make jam, jellies, syrups and to decorate cakes and other puddings

They will store for a day or two in the fridge, and should they need to be stored longer, freeze extremely well. Freezing them on open trays and then bagging, means the fruits stay separate and can then be used in the same way as fresh fruit.

Common diseases of raspberries & solutions

There are some common diseases that can affect raspberries, but these can mostly be controlled if they appear.

Raspberry Viruses

Probably the worst and most difficult problem of raspberries as viral infections are incurable. The only solution is to grub up the plants and burn them.Replace with fresh stock and do not plant in the same place.

It is important to buy stock that is known to be free of viruses, as once infected, the canes lose vigour and crops are much reduced. Viruses are transferred from infected plants by aphids, leafhoppers or nematodes.

Symptoms are yellow mottling of leaves or stunted growth. There is no effective control and infected  plants should be removed as soon as they are no longer productive. Making sure that weeds do not grow nearby is one way of reducing the possibility of infection, as many of the viruses live in other host plants, many of which are weeds.

Raspberry Rust

Raspberry Rust shows as small pustules on the leaves, starting yellowish, turning orange in the Summer and being black by the end of the season. The easiest way to control the disease is to pick of and destroy and infected leaves, and clear up all fallen leaves in the Autumn to reduce the chances of the disease carrying forward into the next season. Bayer’s Fruit & Vegetable Disease Control is effective against rust.

Raspberry Cane Blight

Raspberry Cane Blight is a serious fungal disease which enters the canes through small wounds and leads to die back of the cane.  The first symptom is dead leave sin the summer, followed by a dark brown base to the cane, which becomes very brittle. Bayer’s Fruit & Vegetable Disease Control may be effective, but if the disease is widespread the canes will need to be replaced.

New canes should be planted in another part of the plot, or soil replaced.

Raspberry Spur Blight

Raspberry Spur Blight is a fungal disease where canes develop purple patches and become less productive. Ensuring canes are not overcrowded helps prevention, and again the above mentioned product can be an effective control.

Raspberry Leaf & Bud Mite

Raspberry Leaf & Bud Mite results in yellowish patches on the upperside of the leaves in May, when these mites emerge and canes may develop mis-shapen leaves towards the top. These symptoms are caused by the microscopic mites sucking the sap of the leaves. There is no chemical control, but affected canes usually produce a good crop.

Raspberry Beetle

Raspberry beetle can lead to small dry patches in the fruit towards the stalk end, and sometimes small grubs (6-8mm in length) inside the fruits.

Fruits setting later in the season are rarely affected. If they are a major problem, they can be controlled organically with a pheromone trap, which attracts the male beetles and takes these ‘out of circulation’ or with a spray containing deltamethrin as soon as the first pinkish fruit is visible , and then again two weeks later (Leave seven days before picking any fruit)

Hoeing in spring and summer will bring pupae to the surface and expose them to the birds and other predators, reducing there numbers.