
Material should be removed systematically throughout the tree, should not exceed the stated percentage and not more than 30% overall. Crown thinning does not alter the overall size or shape of the tree. It is usually confined to broad-leaved species. Main Pruning Definitions Crown ThinĬrown thinning is the removal of a portion of smaller/tertiary branches, usually at the outer crown, to produce a uniform density of foliage around an evenly spaced branch structure.

Felling or even just pruning a protected tree without permission from your Local Planning Authority may be a criminal offence.Īlways check for Tree Preservation Orders or Conservation Area restrictions with your local council’s Tree Officer and/or Planning Department before carrying out any works. The British Standards most relevant to arboricultural work are:īS3998: 2010 Recommendations for Tree Work andīS5837: 2012 Trees in Relation to Design, Demolition and Construction - Recommendations.Ī word of caution: Many trees are legally protected. These are very general summaries and the Arboricultural Association can provide more detailed guidance by leaflets and other publications. The three main pruning options are shown below, and after that a glossary of other terms that you may find helpful. Did you know, for example, that a ‘crown thin’ will not reduce the height of the tree? Nor will a ‘crown lift to 4m’.

It is important that clients understand the basic terms commonly used to describe tree work operations so that they can ask for what they want or understand what the arboriculturist is recommending.

Improper pruning can lead to trees becoming unsightly, diseased and/or potentially dangerous. Tree pruning may be necessary to maintain a tree in a safe condition, to remove dead branches, to promote growth, to regulate size and shape or to improve the quality of flowers, fruit or timber.
