Arborworks Ltd Tree Surgery

Crown Reduction
The process of cutting canopy growth back to a side branch, leaving a flowering line, enabling the tree to be maintained at a manageable size for its surroundings. Dead, diseased and crossed limbs are also removed to protect the health of the tree.

Crown Thinning
An intricate process of pruning where a proportion of secondary growth is removed throughout the crown to produce a more open and evenly balanced structure. It allows more light to travel through the canopy and greater circulation of air. Dangerous, dead and crossed limbs are removed at the same time.

Crown Lifting
The removal of branches from the main trunk to allow visibility and access under the canopy whilst preserving the overall form of the tree. Common in parks and fields for maintenance of grassland.

These processes are specialist operations and should not be confused with Topping, an inferior service which seriously threatens the health of a tree. See Reasons not to "top" trees - opposite.

Reasons not to "Top" trees

Starvation Judicious pruning rarely removes more than 1/4 of the crown which does not interfere with the ability of the tree to manufacture food. Topping removes so much that the sensitive crown-to-root ratio becomes unbalanced and the tree is temporarily unable to make food.
Shock The leafy canopy acts like an umbrella which shields the sensitive bark of the trunk from the sun. Removing the canopy can result in damage to the bark tissue from exposure. Neighbouring plants and shrubs beneath can be affected too if their environment is upset by a sudden increase in light levels.
Disease The exposed stubs of a topped tree are vulnerable to attack from insects and fungal spores. If decay is already present elsewhere, the spores will attack the new opening and spread the disease.
Weak Limbs A new limb that sprouts from a truncated limb is more weakly attached than those which develop normally. The weight of the new limb can cause splits vulnerable to disease.
New Growth The sprouts which erupt from a severed limb are more numerous and elongate more rapidly than normally developing shoots. In a short period of time the tree has returned to its previous height with a far denser crown, the opposite of what you are striving to acheive.
Death Some trees are more tolerant of topping than others. An older tree may not sprout so rapidly and the reduced foliage will lead to the death of the tree.
Appearance A tree which has been topped is disfigured. It will never regain its former natural grace and character.
The Real Cost Topping a tree is far easier than applying the skill and judgement of careful pruning. Therefore the initial financial cost is far less. However the true costs are hidden. The aesthetic value of the tree to your property and environment, the cost of removal and replacement if the tree dies, the effect on other plants dependent on the protection of the tree canopy, the risk of weakened limbs and increased costs in future maintenance.

Topping a tree is a short-sighted maintenance procedure. As trees are so long lived it is not practical or desirable.

Pollarding
A traditional woodland management method, that is now finding its way into arboriculture, which involves the removal of all branches and most limbs resulting in only the trunk remaining with, occasionally, a framework of major limbs. A tree which has not been pollarded is called "maiden", referring to the fact that pollarding is normally first performed when the tree is quite young. After a tree has been pollarded some time must be allowed for re-growth, after which the process may be repeated.

Deadwooding
The removal of dead, decaying or diseased branches from the body of the tree. If left unchecked the health of the tree may be threatened and safety becomes an issue.

Branch Removal
Necessary for safety or aesthetic reasons. Early removal of a dead, diseased or dangerous branch can avoid costly problems in the future.