They fruit on the old wood and you can cut off most of the new growth if you want to. I do this after picking the fruit & its always been OK & they bear very heavily. Mine are grown as cordons against a wall and I leave hardly any new growth at all but if you have bushes you could just cut the ends off and any crossing branches. Do mulch them though, and give them some sulphate of potash around late February.

thank you very much