Winter pruning secrets: six plants you need to prune in January

Pruning is done for a variety of reasons: to thin, train, and rejuvenate crowded growth, to promote bigger harvests or more flowers, to control disease by removing infected wood, and to encourage vigour. By January, all deciduous leaves should have been shed, so you can clearly see the plants’ shape as well as any 'problem' growth that should be removed.

While the method of pruning varies according to the type of tree, shrub, or climber, there's one rule that applies to all plants: to remove the 3 ‘D’s – any growth that is dead, diseased, or damaged. Start with that and then move on to the specific pruning or shaping required by each plant. These are the key ones to tackle now:

Apple and pear trees

Bush or half-standard apple and pear trees – those which are free-standing rather than trained to cordon or espalier shapes – really benefit from regular pruning every winter. Otherwise, they become straggly, overgrown, less productive and harder to harvest from. Cutting back branches and shoots in the dormant season will concentrate next spring’s sap flow, resulting in strong growth.

In the first few years of a fruit tree’s life, prune to create a sturdy framework of branches. Medium and large apple trees benefit from having vigorous young shoots cut back and overcrowded branches thinned in winter. Aim to create a wine-glass shape, with evenly spaced branches coming up from the trunk around an open centre. This encourages allows maximum light and air through the tree, helping prevent diseases which would flourish in stagnant air, and boosting fruit ripening.

Formative pruning

• Take out or reduce any branches that are growing vertically upright, as the fruit will be out of reach and difficult to harvest.
• Remove crossing branches that might rub and create wounds which are entry points for disease
• Remove any thin shoots and branches
• Always cut back to the joint with the branch or trunk rather than shortening branches, which would result in a cluster of thin shoots next year

Pruning to boost fruiting

Once the main formative pruning is complete, tackle the smaller shoots of last season’s growth by reducing sideshoots back to between four and six buds from the base. The younger stems are silvery-grey in colour, so are easy to distinguish from the older, brown branches. This encourages the formation of knobbly, spur-like shoots that will bear fruit.

Currant bushes

Regular winter pruning keeps soft fruit bushes cropping at their best.

Blackcurrants fruit best on younger growth, so once bushes are several years old, get in the habit of taking out some of the oldest branches every winter. Take out around a quarter of the thickest, oldest branches, cutting close to the ground. If possible, cut to an outward-facing bud. Aim to create a goblet shape, leaving healthy young branches that will produce large crops in years to come.

Red and white currants. These need similar, but less severe, treatment. Mature bushes should have one or two of the oldest stems removed as described for blackcurrants. Then, reduce the previous year’s stems by around a third to a half.

Grapevines

Pruning vines must only be done right in the middle of the dormant period, from late November to around mid-January, because vines bleed sap freely if done at other times and this is bad for the health of the plant. Grapes form on new growth, so cut the old, fruited stems back to the main framework of the vine.

Deciduous native hedges

Native hedge plants such as hawthorn, blackthorn, hazel, and field maple make magnificent wildlife-friendly hedges, either trimmed to shape annually, or ‘cut and laid’ to create a more solid barrier. Cut back as much or as little is needed. January is the ideal time, once hedgerow fruit has been eaten by birds and mammals, and crucially, before the bird nesting season starts.

To lay a hedge, select stems that are several years old and, using a small sharp axe, cut most of the way through the stem, close to the ground. Then, gently bend them down diagonally, so the sap runs freely through them.

Overgrown deciduous shrubs

Winter is the ideal time to rejuvenate almost any deciduous shrub whose branches are overcrowded in the centre, or to tackle any which have become misshapen.

Assess the shrub and select no more than a third of the thickest stems to take out. Aim to cut these out as near to the ground as possible. Where growth has become tangled, cut long stems into several sections for easy removal. Prune out any stems that rub against each other, aiming to create an open-centred canopy that allows air to circulate freely. Remember to take out any stems that are dead, diseased, or damaged, too.

Renovating mature shrubs should be done over a period of three years, gradually removing the oldest stems and encouraging new, more productive ones to grow up.

Wisteria

Wisteria is a magnificent and large-growing flowering climber, though plants do need to be kept in hand by pruning to avoid becoming a tangled mass of long, thin, whippy side shoots.

By pruning in winter as well as summer, you will encourage the development of short spurs that carry the flowers in spring. In summer, the many lateral side shoots should be cut back to five to six buds from the main stems. Now, in January, these should be cut back further, to two to three buds.