Advice
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Cane and bush fruit training and pruning
Raspberries, blackberries and hybrid berries need pruning and training once harvesting is over in late summer to maximise fruit yields in subsequent years.
Cane fruit are best trained onto a system of post-and-wire supports, using four lines of 12- or 10-gauge steel wire (about 2-3mm (1/8in) diameter) attached to stout posts 75mm (2 1/2in) square, positioned 10m (33ft) apart. Attach the lowest wire 1m (39in) or so above the ground and space those above 30cm (12in) apart.
Summer raspberries work well between double rows of wire 45cm (18in) apart, avoiding the need for tying in. Otherwise, canes are tied to the wires with string or twine. In confined spaces, less vigorous cultivars can be grown over an arch, and compact hybrid berries (such as the thornless loganberry) can be grown in a fan.
Raspberries
Training: Train canes to one side of the wires, leaving the other side free for training the new canes that will grow next season and fruit the following year.
With a double post-and-wire system, the new and old canes can be tied to opposite sides of the row. Keeping the current and the previous years’ canes separate makes picking fruit and removing old canes much easier.
Pruning summer-fruiting: Summer raspberries fruit on two-year-old canes. Cut back fruited canes to ground level after harvesting, to make way for the young canes that will fruit next year. Do not leave old stubs, and select the strongest young canes, removing the others. Aim for 8-10cm (3-4in) spaces between approximately eight chosen canes per plant.
Suckers between rows should be removed; cut out those near plant bases and dig or hoe out those further away.
Pruning autumn fruiting: Autumn raspberries fruit on current-season canes, so can be cut back completely after harvest. Regular removal of fruited canes throughout the season can extend fruiting into winter, when all remaining canes should be cut to ground level. They will re-shoot in spring.
Blackberries and hybrid berries
Hybrid berries include loganberries, tayberries and boysenberries. They are mostly crosses of blackberries (Rubus fruticosus) with other Rubus species.
Training: Vigorous berries can be trained with the old and new canes running in opposite directions along the wires. Canes can be looped vertically between the horizontal wires to save space (and make attractive patterns), but allow space between the canes for light and air penetration.
If space is limited, new canes can be bundled together to one side in their first year, and trained to the other side in their second year to replace the fruited canes once these are pruned out.
With a fan, one half should be old canes and the other half new canes. It is harder to separate old and new canes when growing canes over a garden arch or wigwam, so consider a thornless cultivar if doing this.
Pruning: Blackberries and hybrid berries fruit on two-year-old canes like most raspberries. Cut back fruited canes completely after harvesting, and train the young canes along the wires. Keep one- and two-year-old canes separate for easier harvesting and pruning.
Blackcurrants
Training: initial pruning - grow as stooled bushes - i.e. a number of shoots growing from ground level. Plant 2.5cm (1in) deeper than before then cut back all shoots to 2.5cm (1in) from soil level.
Pruning young bushes: prune in winter. For the first three years, if growth is strong prune lightly (i.e. removing weak and low-lying growths), but if growth is weak prune hard, cutting at least half the shoots to ground level
Cropping - mature bushes: prune in winter, cutting out one third of the growths annually - old unproductive wood, weak and low-growing stems (to stimulate strong growth from or near ground level).
Gooseberries and redcurrants
Training: both produce fruit buds on spurs from older wood and at the base of previous summer’s growth. They are trained to form a permanent branch framework, often as cordons, but usually as open-centred bushes on short stems, with 8-10 main branches.
Pruning: summer prune (mid-June/mid July), shortening current season’s growth back to 5 leaves except those needed to extend or form branches. In winter spur prune the same shoots, reducing to one to three buds from the base, and shorten branch leaders by one quarter (to a suitably positioned bud, keeping the centre of the bush open).
Further information
Brogdale Horticultural Trust, Faversham, Kent ME13 8XZ are the NCCPG National Collection holders of apple, pear, plum, cherry and many other fruit collections.