When I first started growing raspberries I had a real problem determining what I should be pruning out and what I should be leaving. It sounds quite simple until you stand in front of those canes and have to start cutting…
I’ll start with spring fruiting Raspberries as they are really easy. Raspberries grow in a bush-like form i.e. they really don’t need much, if any support. Basically a spring or early summer fruiting raspberry will fruit once a year. The canes that produced the fruit will not fruit again. In the winter these canes will go a dry grey colour and look “slightly” different to the younger ones that haven’t fruited. Prune these grey ones off at ground level leaving around 10-12 young canes to fruit in the coming season.
Twice fruiting Raspberries are more difficult to manage but so worth it! Summer/autumn fruiting Raspberries are treated differently as the one cane will fruit at two different times over its lifetime. In winter prune back the cane that has fruited by around a third. This cane will then fruit the following summer. Only remove this cane once it has fruited in autumn and then the following summer. During the spring new canes will be produced that will fruit in the autumn. Once you have had your Raspberry bush three years you will have some canes that are fruiting in summer and some that are fruiting in autumn. In the winter also prune out any weak canes. After pruning you should have around 10-12 canes per bush.