Types of pruning to the crown

Crown Reduction

The one we are asked for most often. 'My tree's too big, can you make it smaller?'

Of course we can. A crown reduction is where the tree is reduced as a whole. It used to be specified in percentage terms, which can sometimes cause misunderstandings. Nowadays we tend to say for example that the foliage be reduced by 1 metre (or whatever distance) all over.

Crown Thinning 

Crown thinning is the removal of a small portion of secondary and small live branches to produce a uniform density of foliage around an evenly spaced branch structure. It is usually confined to broad-leaves species. Crown thinning includes crown cleaning and does not alter the overall size or shape of the tree. Common reasons for crown thinning are to allow more light to pass through the tree, reduce wind resistance or to lessen the weight of heavy branches.

Crown Cleaning 

The removal or dead, dying, diseased, broken, crowded, weakly attached and low-vigour branches as well as climbing plants (eg ivy).

Crown Lifting 

Crown lifting is the removal of the lowest branches and preparing of lower branches for future removal. Good practice dictates crown lifting should not normally include the removal of large branches growing directly from the trunk as this causes large wounds which may jeopardise the long term future of the tree. Common reasons for crown lifting are to bring more light and give access for traffic. In the UK common practice dictates clearance for vehicles is 5.2 metres (17 feet), and for pedestrians 2.5 m (8 feet).

Formative Pruning

Pruning during the early years of a tree's growth to establish the desired form and/or correct defects or weaknesses.

Pollarding 

A frequently misunderstood term, and used in two different contexts. Traditionally and still commonly used this term describes the removal of all branches from the trunk. Mature trees that have not been pollarded before are generally not suitable candidates for pollarding due to the large wounds that such treatment produces which may jeopardise the long term future of the tree. A less frequently used definition can mean the regular (annual or biannual) pruning back of small branches to the same point resulting in the formation of a 'pollard head'. Pollarded trees usually require regular treatment of re-growth.

Lopping and Topping

Something we don't do. This is the practice of simply hacking the end or top off a limb. It is a brutal assault on the tree and results in a rush of epicormic re-growth which is weakly attached.