Pruning raspberries: expert tips
Cutting back raspberries requires some skill. Here are all the tips on pruning raspberries from the right time to prune to detailed instructions.
Raspberries (Rubus idaeus) are one of the most popular berries to grow and are cultivated in many gardens. The red to pink fruits are very refreshing, especially in summer, and are quite easy to grow. However, in order for the prickly plant to produce the desired yield, it is important to cut the raspberry canes at least once a year.
In the following, we discuss when and how to prune raspberry bushes so that they can produce a high yield. All of the important information is summarised in the table below. If you are unsure which type of raspberry is growing in your garden, you can find advice on that below too.
When to cut back raspberries: in spring or in autumn?
Before pruning the plant, it is recommended to find out which type of raspberry you are growing. There are several types of raspberries: summer raspberries, autumn raspberries and the so-called two-timer raspberries, i.e. the double-bearing specimens. The difference between these types is in the time of harvest. Depending on the raspberry type, different pruning techniques are carried out at different times.
- Summer raspberries: these raspberries ripen from June to July. Their berries form exclusively on the two-year-old shoots. The older, worn, biennial shoots should be pruned in summer after harvest. The young shoots are thinned out in spring after last frosts are gone.
- Autumn raspberries: these ripen from August to October. The berries always grow on the annual shoots. They should be pruned in autumn after harvest.
- Two-timer raspberries: this group of raspberries, also referred to as everbearing raspberries, is a cross between the autumn and summer raspberries and bears its berries on both annual and biennial shoots. This means that a smaller amount of fruit can be harvested once in summer and once in autumn. Two-timer raspberries should be cut back in spring.
Pruning raspberries: instructions for different raspberry types
The following sums up when and how to cut back raspberry bushes. In order to explain raspberry pruning techniques and the corresponding time frames for pruning clearly and without causing any confusion, we have summarised everything in the table just below this paragraph. Depending on the raspberry type, pruning might have to be carried out more than once a year. Do not fret, though, once you get the gist of pruning and understand the logic behind it, cutting back raspberries will become quick and easy.
|Raspberry type||Time for pruning||Technique
|Two-timer raspberries (everbearing raspberries)||Spring||The biennial shoots, which bore fruit last summer and are now clearly distinguishable from the fresh shoots, are cut off.|
|Summer raspberries||After the harvest in summer||By the time of harvest new, green and prominent shoots have usually formed. These are the shoots that will bear fruit next summer. Do not prune them! Instead, after the harvest period, cut back the old and brown shoots, which bore fruit previously.|
|After the last frost (around March, depending on the climate zone)||Select ten of the healthiest looking shoots (left uncut from the previous autumn) per one metre to leave on the plant. If there is a large selection of beautiful shoots, choose them in such a way, so that each shoot has enough space to grow and bear fruit. The remaining shoots are all cut off close to the ground. Although this method might seem radical with older raspberry bushes, leaving ten (max. twelve) shoots is ultimately best for the health of the plant and will not negatively impact its yield.|
|Autumn raspberries||Autumn||Autumn raspberries make pruning even easier than summer raspberries. After harvesting in autumn, simply cut off all shoots close to the ground. Next spring, new shoots form and bear berries in autumn. If your plant is healthy and there is no risk of diseases being transmitted to the new shoots in spring, you can leave them. They might be used by insects as refuge in winter.|
|All types of raspberries||Autumn||As a matter of principle, diseased shoots should be pruned in order not to infect the whole plant. However, if the leaves are yellowish, you do not need to cut them off. Yellow leaves can be a sign of a nutrient deficiency (for example magnesium deficiency). This can be remedied by applying organic fertiliser in autumn or spring (until around May).|
A tip that applies to all types of raspberries: if the tendrils grow above your head (i.e. taller than two metres), prune them away above the tendril support in late summer at a height of about 1.5 metres. This will promote bud formation in the coming year on the remaining shoot.
What type of raspberry have I planted?
In principle, autumn raspberries can be cut back in the same way as summer raspberries. However, this does not work the other way around. Summer raspberries that have been completely cut will not bear raspberries next year, as they form their fruit on the two-year-old shoots.
For this reason, we recommend the following: if you are not sure whether you have planted an autumn or a summer raspberry, simply prune your plant like a summer raspberry. In this way, you are playing it safe and next year you will have at least one harvest in summer, if not a second harvest in autumn. If the plant bears an additional harvest in autumn, you will know that you have an autumn raspberry in your garden.
Cutting and propagating raspberries at the same time
If you have a raspberry plant in your garden and you decide to plant more, it is definitely worthwhile to grow new plants from cuttings. You can remove the cutting when thinning out the mother plant by pruning. In this way, you can kill two birds with one stone. In early summer, cut off several slightly wooden shoots from the plant and place them in some soil to grow. A branch should have at least two leaves if it is to be used as a cutting. With a little luck and if the conditions are right, the cutting will develop roots in a few weeks and the new raspberry plant can be planted out in the open. Another option of raspberry propagation is to use raspberry runners.