growing-Raspberries-stand You will need a fence and wire system to support the plants. The usual arrangement is to use posts about 15ft/5m apart and stretch wires between them at two or three heights, usually about 60cm apart vertically. This system is supposed to allow you to tie in the old canes to one side, and the new canes to the other during the growing season, so that you can easily separate them in when you come to cut them back.