All tree pruning has an impact upon tree health and there needs be good justification for it. We will consider all requests for pruning but we will take into account the benefits and weigh them against the impact upon the tree. We will do any necessary work in line with current British and European Standards: BS3998 ‘Recommendations for Tree Work’ and the European Tree Pruning Guide. We will not do any work, which exceeds these recommendations.
Where there is no alternative we will carry out pruning works to comply with legal requirements to achieve clearances over roads. Pruning may also be carried out in exceptional circumstances where branches interfere or obstruct street lights, CCTV cameras and overhead cables for example. However, we do expect installation engineers to take account of trees and their future growth before they install their apparatus.
These are some of the tree pruning techniques we use…
Crown Thinning
This involves removing some secondary branch growth to create a less dense crown. Crown thinning is sometimes recommended if there are complaints about a tree blocking the light, but is often unsuccessful because the amount of branch wood we remove without harming the tree is minimal – the European Standard advises a maximum of 15%.
However, crown thinning can enhance a tree’s appearance by creating a more visually balanced crown, and we will do this work where necessary.
Crown Lifting
This involves removing some of the lower branches beneath a tree’s crown. We often do this to trees near footpaths and roads to allow traffic to pass by safely. It can also help more daylight to pass through a tree. We will not usually lift lower branches to more than one third of the tree’s total height. However, we may have to do this on roads to comply with legal requirements or to make a clearance around streetlights and vision splays.
Crown Reduction
Crown reduction reduces a tree’s crown while still maintaining its natural shape. This is different to ‘topping’, which is not acceptable. We will not normally do crown reduction work because we favour removal and replanting with a more appropriate species instead (see “Tree Felling”) since this is a more cost effective, long term solution. However, crown reduction is often used where part of a tree touches, or is very close to, a building. We will only reduce part of the crown or specific branches in these circumstances.
We won’t usually prune back trees that overhang a neighbouring property, unless there is particular risk associated with the overhanging branches. Property owners are entitled to cut back any branches overhanging their boundary, as long as they dispose of all the cuttings properly.
We can combine crown reduction with thinning and lifting when trees are blocking daylight, but only in severe cases where it significantly affects residents’ quality of life.
Crown Cleaning
This involves removing dead or diseased branches. We will only do crown cleaning where there is a real possibility of falling branches causing accidents or injury, or if diseased branches threaten the tree’s health. Dead wood has immense ecological value and we don’t usually remove it from trees, which are away from very public areas, for example in quiet areas of parks and woodlands.
Pollarding
This is an ancient tree management technique that starts early in a tree’s life. It involves pruning back branches to the same point on a regular basis to form ‘pollard heads’ which store energy.
Pollarding needs to be done at intervals of between one and five years.
Many trees lining Derby’s streets have been pollarded and we will continue this for the foreseeable future.
There are instances when we may decide that pollarding is not necessary or appropriate, for example if trees
- have enough space to develop naturally
- have not been pollarded for over five years to allow them to grow on.
We can’t pollard older trees if they have not been managed as pollards. Causing extensive decay, this would threaten the tree’s entire structure and would be similar to ‘topping’, which is not acceptable.
Root Pruning
Occasionally, tree roots can damage footpaths and pavements. In these cases we can prune the roots. However, if root pruning is likely to threaten the tree’s health or stability, felling may be our only alternative.
Contact us
By telephone: 01332 715537
By fax: 01332 641512
By email: trees@derby.gov.uk