When to prune trees

Winter: the main pruning season

For most deciduous trees, such as oak, ash, beech, lime and many fruit trees like apples and pears, the best time to prune is while the leaves are off, from late autumn to late winter. The tree is resting, so it loses less energy, and with bare branches it is far easier to see the structure and decide which limbs should go. There are also no nesting birds to worry about in the depths of winter.

Avoid pruning during a hard frost, when wood can be brittle and cuts may split.

Trees that are better pruned in summer

A few trees do better if they are cut when in full leaf.

• Cherries, plums and other stone fruit: summer pruning lowers the risk of silver leaf disease
• Walnut and birch: these bleed sap heavily if cut in late winter or spring
• Maples: also prone to bleeding, so they are usually cut in late summer or autumn

Spring: usually the time to wait

Spring is generally the least suitable time for major pruning. The tree is putting its stored energy into new leaves and shoots, and heavy cuts at that point weaken it. Spring is also the start of the main bird nesting season. Light work, such as removing a dead branch, is fine, but larger reductions are better left for later in the year.

Nesting birds and the law

All wild birds, their nests and eggs are protected by law. The main nesting season runs roughly from March to August, though birds can nest outside it. Before any work in that period, the tree should be checked carefully. If an active nest is found, the work around it has to wait until the young have left.

Protected trees and conservation areas

Timing is not just about the tree. If it is covered by a tree preservation order, you need consent from the council before pruning. In a conservation area, you normally have to give the council notice before work on most trees. Both take time, so it pays to check well ahead of the season you want the work done in.

When to leave a tree alone, and when not to wait

Some trees are best not pruned at all if they are healthy and not causing a problem. Cutting for the sake of it can do more harm than good. On the other hand, a branch that is cracked, hanging or dead over a path, house or road is a safety issue, and should be made safe whatever the time of year.

Fruit trees: a quick guide

Apples and pears are usually pruned in winter to shape the tree and encourage fruiting wood, with a light summer trim for trained forms such as cordons and espaliers. Plums, cherries, apricots and other stone fruit are pruned in summer, after fruiting or on a dry day, to reduce the chance of disease. Young fruit trees need formative pruning in their first few years to build a strong framework.

Hedges and trees are different

Hedges follow their own timing, usually trimmed between late spring and early autumn with a check for nesting birds first. Trees need fewer, more considered cuts. If you have both, the timing will often differ: a winter crown lift on a tree and a summer trim on the hedge beside it is common.