Tree Pruning

 

I get tired of being told by people that the mature trees in their garden need lopping, topping, pollarding, trimming down etc, and being asked to provide them with a quotation for carrying out general assault to their beautiful trees. On questioning their motives, the usual responses include; the trees haven’t been cut for a long time, they cast too much shade, or even that they drop all their leaves in the autumn!

 

Trees are not like roses, which require frequent and regular pruning. Heavy pruning will invariably cause damage to the tree, which may not recover from the work. Clearly pruning is valid and warranted in a number of situations, but far too many trees are excessively and needlessly cut. Our landscape is being systematically denuded by people allowing their trees, which can provide amenity for many people, to be heavily pruned for misguided, short term reasons.

 

Trees should not be unnecessarily pruned. Their beauty can be decreased, and damage can be caused. Pruning can provide sites for infections to enter the tree, such as decay fungi and bacterial infections, which may ultimately render the tree unstable. Another problem which is often associated with pruning, is the re-growth. Around cut branch ends, clusters of new shoots tend to develop which are unsightly, and grow far more vigorously than usual twig extension growth. This establishes the need for future pruning, on a regular basis, with all the associated problems described above, not to mention the financial implications.

 

But there are occasions when pruning is necessary, and the benefits achieved will outweigh any negative effects on the tree. The consideration of tree safety is an important one, and tree owners have a legal duty of care to do what is reasonable to ensure that their trees are not dangerous.

 

Clearly there is ambiguity here, as no tree can be guaranteed safe however apparently secure its structure is. Strong winds can cause damage to the healthiest of trees. A qualified arboriculturalist however should be able to identify many weaknesses within the tree structure, by reading its ‘body language’.

 

Trees may have imbalanced crowns, heavy lateral branches, weak branch unions, internal fractures, decayed limbs, trunks, butts or roots, large quantities of dead wood or other insecure branches. Pruning may bring the trees to an acceptable level of safety. or removal may be the only valid option.

 

I have been asked by the editor to assess how much damage to trees could have been avoided during the storm of October 2002. Certainly some of the call out work that we attended to could have been predicted had an expert been called in prior to the event. These included trees with decayed roots and butts being blown over, and limbs with very tight forks breaking out of the trees. It was interesting however that the majority (perhaps 60-70%) of the damage was caused to mature oak trees which would have appeared to be in good condition before the storm. Small to large limbs within the crown fractured, and either broke out of the tree altogether, or remained lodged within the tree. Why this should affect oak, which I would assess to be one of the stronger trees above other species is interesting. It may be that oaks, unlike others were very late in loosing their leaves last autumn, and still had their leaves during the storm, which gave them an increased wind resistance.

 

Pruning can be useful in reducing nuisance when trees cast heavy shade. If they have crowded crowns, with numerous branches, these can be thinned out by up to 30%. This improves light levels, while maintaining a natural crown profile. Low branches, or branches close to or touching buildings can be removed in order to reduce nuisance.

 

Many of the nuisance problems that trees are perceived to cause, are created by fundamental errors of planning. Unsuitable tree species maybe planted too close to buildings, or unsuitable buildings are put too close to trees. This invariably leads to the tree owners having their trees topped, lopped or heavily reduced. The best solution may be to remove the tree, and re-plant with something more suitable instead. It is amazing how many young cedars, and Christmas trees, you see in tiny gardens very close to buildings. Trees need space.

 

Tree owners should consider having their trees assessed by an expert, if they are taking their responsibilities as a tree owner seriously. Clearly, this is more important where trees have the potential to do more damage should they fail. A tree with large dead branches may not be a problem, if at the end of a back garden, and very few people ever go close to it. Keeping its dead wood would be worth considering in order to benefit wildlife. The same tree however close to a road would clearly need more frequent inspections, and remedial work taken where necessary. Local Authorities should be able to recommend suitably qualified, local arboriculturalists, or the Arboricultural Association has a list of approved contractors and consultants.

 

I strongly believe that people should be less eager to prune, pollard, top, hack their trees. People need to love the beauty of natural looking trees, even if it does mean the loss of some light and leaves on the lawn. Love your trees, love your leaves. Get a compost heap.

 

By Patrick Stileman