How to prune trees

General tips

• Most deciduous trees are best pruned when dormant, in late autumn or winter. Don't prune in early spring, as many trees bleed sap if cut at this time of year.
• The exceptions to the 'deciduous tree' rule are maple, horse chestnut, birch, walnut and cherry trees which all bleed extensively, even towards the end of their dormant season, so prune these in mid-summer after new growth has matured.
• Conifers require little or no regular pruning except the removal of dead or diseased branches in late summer.
• Please note that major surgery, chainsaw work and any pruning which is substantial, high, inaccessible, or requires a ladder, should be done by a qualified and registered expert, both for your own safety and also for the long-term health of your tree.

Pruning techniques for different groups

Young trees

• A feathered tree such as a sorbus has an upright trunk and a balanced pattern of horizontal branches running from top to bottom.
• Each year, check for shoots growing at odd angles, extra shoots growing from the top of the main trunk, or basal shoots (strong shoots coming from the base which deprive the tree of nutrients).
• All of these shoots need to be removed.
• Young standards like cherry trees are trained in the same way, but the lowest branches are cut off until a clear trunk has formed.
• In the first year remove the lowest third of the tree's branches, and shorten those in the middle third by half. Remove these latter branches in the following year.
• By the fifth year the trunk should be developed, so prune branches out from the tree's crown to produce an open pattern of branches.
• Some trees, especially those grafted onto special rootstocks, produce suckers, which are secondary shoots growing from the roots. As these may exhaust the tree, pull each one up while it's still small, after first exposing the point where it joins the root.

Ornamental trees

• Pollarding and coppicing are traditional techniques that are used for timber production, but they're also useful when pruning ornamentals grown for decorative bark or leaves. It can also be used for keeping trees trimmed to a fixed height.
• Coppicing involves pruning growth back to, or near, ground level in winter and is used for coloured willow and hazel varieties.
• The same trees respond to pollarding, which is a taller version of coppicing with growth cut back to a short trunk.
• Eucalyptus and lime are often pollarded every two to three years to maintain a compact size or smaller foliage. Remember to feed your tree after pruning to encourage plenty of new young growth.

Conifers

• Most standard conifers develop without the need for pruning, but you may need to prune out any damaged or distorted growth.
• This is best undertaken in autumn or winter. If a tree forms two stems, select the strongest, most upright shoot and cut out the competitor at its base.
• You should remove any plain green shoots which appear on variegated conifers, and any abnormally-shaped shoots on dwarf and prostrate conifers.
• Patches of dead or brown foliage need to be taken out and any gaps can be disguised by tying nearby shoots together so they grow across the pruned area.

Watch video

In this video Toby Buckland shows how to prune a tree.

Tree Preservation Orders

Trees of outstanding worth or beauty are often covered by a Tree Preservation Order (TPO). This restricts the amount of pruning that may be done without permission from your local planning authority. Contact your local authority for their arboricultural services department to check the TPO register before commencing work on a tree.