• To produce a given length of the main stem, or trunk, free from branches
• To help the tree form a satisfactory well-balanced crown
• To reduce the weight or alter the shape of the crown, if it is too large
• To remove diseased, dead or dying branches
• To reduce leaf surface and therefor reduce the demands on the root system
• To remove damaged branches
• To prevent the branches interfering with overhead cables, buildings, passing traffic, and to make the tree safe

Removal of large branches

Under certain circumstances it may be necessary to remove large branches from a mature tree.

Roping and Slinging

In some cases the branch must be roped to prevent it damaging the tree itself, nearby buildings or other trees.

How does a dangerous tree differ from a defective tree ?
Most trees have defects, but the vast majority do not render a tree dangerous.  Defects may include minor dead wood where squirrels have stripped bark or minor decay pockets where bark has been damaged and the tree has suffered bacterial or fungal infection.  It is the type and extent of the defect that is important in determining whether or not a tree is dangerous.

What are the symptoms which can make a tree potentially dangerous/hazardous ?
There are a number of defects which, depending upon their extent, may be regarded as potentially hazardous.

Is a tall tree dangerous ?
No.  A tree will grow (within its species limits) as large as the space, light, water, nutrition and oxygen available to it permits.  Trees cannot grow too tall – except in human perception.

Is a leaning tree dangerous ?
Not necessarily.  One of the reasons a tree grows with a lean is because it is in close competition with another specimen and has been forced to grow at an angle to chase the light.  In response the tree lays down denser wood on one side of its trunk.  There may be a problem however if a previously vertical tree suddenly develops a lean.

Is a hollow tree dangerous ?
Certainly some hollow trees may have so little healthy tissue surrounding the hollow area that they must be regarded as dangerous, but this is by no means the norm.  Trees do not become hollow overnight – it can take decades – and while the centre of the tree (the heartwood) may be decaying, the tree continues to lay down healthy wood (sapwood) around the outside of its trunk.  This results in the formation of a cylinder, the strength of which depends upon the percentage of healthy to unhealthy tissue.

Do I need Council permission to cut down a dangerous tree ?
In law you do not need the permission of the Local Planning Authority to cut down a tree which is dead, dying or dangerous.  However anyone proposing to cut down a tree because of these reasons is strongly advised to give the Local Planning Authority five days notice before carrying out the work, except in an absolute emergency.  If work is carried out to a protected tree because of these reasons, the owner or agent must be able to prove that the tree was dead, dying or dangerous and, if it came to a prosecution case, to prove this in court.  This can be using photographs, keeping sections of decayed wood and any other relevant evidence. 

Unlike a thinning cut, a drop-crotching cut does not cut back to a natural boundary, this means that decay can spread quickly inside cut branches, for this reason it is best not to perform crown reduction if at all possible.

In many instances, canopies cannot be properly reduced in size to the extent desired and certain species such as Beech do not lend themselves to crown reduction, without special techniques such as pollarding.

Over pruning of the trees to create the desired effect, with heading and drop crotch cuts, can initiate decay in the trunk or branches and stimulate rapid epicormac growth that fills in the canopy as it quickly grows to it’s original size.

It is very difficult to use crown reduction to permanently maintain a tree at a smaller size without causing the tree to decline. Consider pollarding to reduce and maintain the height if the tree is young. However tree removal and replacement with a smaller maturing plant may be the choice that minimizes the input of resources.

When a customer wishes to reduce the height, crown reducing is much preferred to topping. Crown reduction should not be used to reduce the chances of the tree blowing over in a storm. Thinning is the preferred method to minimize storm damage of an otherwise structurally sound tree. Crown reduction can be considered when the root system of a large maturing tree has substantial decay making it potentially hazardous or on a tree with a high rating. We would suggest considering pollarding or planting a smaller maturing tree for the site.

How is crown reduction achieved?

The objective is to make cuts so that the foliage is left intact on the outer edge of the new, smaller canopy ideally, pruning cuts should not be evident when you stand back from the tree after pruning. Topping, shearing, tipping, and rounding over are not appropriate techniques for reducing the size of the tree because they compromise the tree’s structure and can cause decay.

We would recommend when removing more than 30% of the foliage, that you consider dividing the job into 2 sessions, around 12 months apart to minimize sprouting and starch removal from the tree.

To reduce the size of a tree with drop-crotch cuts, we shorten the branches that extend beyond surrounding branches.  This maintains the approximate original shape of the tree. The tree is simply made smaller. The longest portion of the main branches will be cut back to an existing, smaller lateral branch that is large enough to assume the role of the branch.  This is normally 1/3 to 1/2 the diameter of the removed branch. Excessive sprouting accompanied by die back or decay often occurs  if you cut back to a branch that is too small. It is unreasonable to expect more than about a 15-20 percent reduction in size of  canopy from a properly executed crown reduction. This is a time consuming technique and is more an art than a science.  Our professional arborists are proficient at this technique and can take an ordinary tree and create a unique specimen.
It requires substantial talent to perform this operation; of course this is a temporary measure because the tree will quickly revert to its natural size. Crown reduction is quoted as percentage of leaf space not volume or height.

Bracing is necessary under the following circumstances;

• To provide support to large branches which might otherwise break under their own weight
• To prevent or arrest the splitting of forked branches
• To brace the crown of a tree
• To reduce the effect of wind on the branches of a large tree

Methods of Bracing

There are basically two types of bracing;

• Cable or flexible bracing
• Rod or inflexible bracing

There is also the provision of ground support with props, which is also known as vertical bracing.

It is important for reasons of safety involving persons or property to have deadwood in your tree regularly inspected and cleared of any danger or liability of falling branches.

Deadwooding involves the removal of all dead, dying, broken or diseased branches from the tree. In performing this, the tree is more structurally sound to adverse weather conditions and visually is more aesthetic. Deadwooding also increases the amount of light and air circulation within the canopy of the tree, reduces the risk of pests and disease, improving the overall health and beauty of the tree.

Most evergreen formal hedges like to be trimmed two or three times a year, while they’re actively growing. Conifer hedges such as leylandii need regular pruning or these fast-growers will soon outgrow their location.

Hedge Trimming Laws

Not many people know, but hedges can be protected by very similar laws to trees, and so when major work, or indeed removal is required, checks should be made to ensure that no laws are in danger of being broken.