Dead, dying or diseased wood, stumps of broken branches, crossing/rubbing branches, unwanted epicormic shoots, climbing plants, e.g. Ivy, and rubbish accumulated in branch forks should be removed. Other objects such as wires, clamps or boards should also be removed when this can be done without inflicting undue damage on the tree concerned.
Ivy may have to be removed from trees, either entirely or from ground level up to 1m, so that they can be fully inspected, as Ivy can hide decaying or weak structures.
NOTE: Ivy is the commonest climbing plant found on mature trees and does not generally cause any physical damage to the support tree. However, when ivy grows into the crown of a tree it will provide increased resistance to wind and fracture of the tree may be more likely to occur. It can also suppress the internal secondary growth and will sometimes overtake the host tree especially yew trees, thus limiting photosynthetic uptake. This is usually a problem with small trees less than 10m tall.
Other climbing plants
Other climbing plants such as spiralling shoots of honey-suckle which constrict the stem, or matted shoots of clematis or Russian vine, which blanket the crown, should be removed from young trees as a matter of course. Extensive infestation in larger trees should also be addressed.
Caution should be exercised in the use of bracing. Its application or alteration in any given situation should be subjected to expert evaluation to compare the effectiveness of bracing with possible alternatives, in order to arrive at the best and safest remedial treatment.
NOTE 1: Tree surgery experience indicates that the introduction of artificial support into a tree may, in appropriate circumstances, extend the tree’s safe life and/or lessen the damage done should the supported part collapse.
NOTE 2: Some trees can have structures susceptible to climatic damage. For example, cedars tend to produce plates of foliage at the end of the branch and such branches hold snow and may snap under the weight. It is not uncommon for repeated fractures to occur in such trees and as a result pruning or removal of the tree can be more appropriate than bracing. The upright branches of Cypresses can be permanently displaced by snow. Such branches can be supported with netting or pruned out.
Water pockets and cavities filled with rubbish or rotten (soft) wood
If a cavity is not filled with water it should be cleared of rubbish and rotten (soft) wood, as such material may encourage survival of wood-rotting fungi in a tree. Removal of wood to expose a sound surface should not be attempted since it is likely to breach the natural defences of a tree against wood-rotting fungi.
NOTE: Water filled cavities do not need to be drained because continuously wet and stagnant conditions are not favourable for wood-rotting fungi.
Prevention of use of cavities by birds and animals
Small aperture wire mesh or expanded metal, when secured over the opening of a cavity to prevent entry and use by birds and animals, and accumulation of rubbish, should not prevent natural callus formation around the edge of the cavity. The method of securing should allow easy removal of the covering so that the cavity may be examined to assess the extent of decay, and the safety, of the tree or the presence of wildlife.