Tree Trimming

Trees Safely reduce their size

Trees: Safely reduce their size

Gardeners need to decide whether it is worth reducing the size of Trees Safely that outgrow their space. Although this is often done by pruning, it can be difficult and costly. Alternately, you can replace the tree with one that suits the space. However, this is not always feasible.

Ideal for:

If a tree is outgrowing its garden space, it will have to be cut down in size. It is best to do this sooner than later. The longer it remains, the more difficult it will be to prune and the less likely it to recover.

If they have branches that are dead, diseased or cross-dressed, trees might also need to be trimmed and reduced in size.

It is best to keep shrub and tree growth under control by regular pruning. However, this can be difficult if you have overgrown trees or shrubs that are being inherited from a new garden.

How to reduce trees

For many trees, it is best to prune in the late summer because healing is fastest. Take magnolias or walnuts as an example. To reduce the risk of silver-leaf disease, prune Prunus (cherry), trees in mid-summer.

Winter pruning of deciduous trees is much easier because the branches are visible. However, it is better to do this before Christmas. Later pruning can lead to bleeding.

How to reduce the size of trees

There are many tree pruning options available, depending on the tree and its intended effect. These are listed from the easiest to the most labor-intensive.

  • A complete trimming in spring and summer: This is not recommended for evergreens or smaller formal trees. You will need to do this every year. A long-handled hedge cutter is an option for these smaller trees.
  • Pruning trees that are dormant: This involves reducing the side-branches throughout the tree to make it more attractive and smaller. This allows light in and helps reduce wind damage to the tree. It also gives you an opportunity to remove damaged or diseased wood. You can achieve a balanced result by taking your time and carefully evaluating the impact of each branch being removed. This is not recommended for silver leaf-prone trees.
  • Pollarding This extreme form of pruning removes the entire crown or head. It can produce beautiful small trees but it comes with repeated pruning.
  • Crown Lifting: By removing lower branches, you can lift the crown and enjoy the shade of the tree.
  • Crown thinning: Thinners can thin the crowns to allow more light in.

Professional arborists are best if branches that exceed the wrist’s diameter need to be removed. A professional is the best person to do any of these tasks: crown lifting, pollarding, and crown thinning.


It is a common mistake to do an all-over trim without considering cutting side-branches. This results in unsightly regrowth that spoils the tree’s shape. These shoots will need to be trimmed to allow for the growth of new shoots and to restore the tree’s attractive shape.

  • In excess of the recommended amount, it can lead to vigorous growth. This is often caused by over-zealous pruning.
  • Coral spot can appear on the stubs of poorly cut branches.

RHS tree experts do not recommend pruning or using wound paints. They may inhibit healing and encourage rotting. The ‘collar’ of the branch should be preserved intact to encourage healing. This is the area where natural healing takes place most easily. Make an angled cut at the trunk, so that the collar is not removed.