Thursday 30 April 2009
Pruning trees and shrubs is a subtle and evolving art.
While we could spend many pages debating the intricacy of bonsai or the angles of espalier, we should focus on everyday pruning.
Many times when I have properly pruned a tree a client will comment “it hardly looks pruned”. I always take this as a complement, and will explain the cuts and the rationale behind each one. When I first took my tree pruning license, the rule of thumb was no more than 33% of the crown in any one pruning session. Although it was a while ago that I took my tree pruning exam and I'm sure I wasn't number 007, I did have a license to prune. Fortunately most of the pruning was done by hand and the amount of over pruning was limited by your own strength.
It matters little if you use a bucket truck or climb the tree if you do not have a sound knowledge of the tree and its growth habits and the results of pruning it. Modern equipment increases the potential to do great harm to trees.
The 33% maximum amount pruned has been reduced to 25% and this is stressed as the extreme maximum. On more than one occasion I have suggested that the tree should be removed if you really don't want any of the branches or leaves on it. Truthfully there are some trees that are in the wrong place and may need to be removed. However if you love trees and see the great benefit that they provide, a small amount of pruning will help these giants to live with you.
Returning to the problem of over pruning, if your tree ends up looking like an ancient Greek statue you probably have missed the point when it comes to pruning. The amount to prune is always a concern for the skilled arborist. Many times potential clients will suggest doing radical cuts and extensive pruning that would undoubtedly result in damage or death of the tree. Unfortunately people seem to think that by over pruning they can get better value by avoiding future cuts. I call this the “ pound of flesh “ concept, as in “If I'm gonna spend the money, I want to see a pound of flesh”. This logic would work if you were carving stone or chopping concrete into small rocks. Trees are living dynamic organisms that contribute ascetically to our environments. The living tissue you remove is essential to the tree to create and store energy. Unfortunately the more you prune the more the tree will respond by putting out new and often uncontrolled growth. Any amount of pruning injures the tree and will create a response from the tree, managing these responses is the real art. One should always discuss the reasons for pruning and the expected results at great length with their arborist before you decide to prune. Once you have removed a branch it will never grow back and restoring form may be difficult.
Prune little, prune often is a better strategy in the long run. A few select sell placed and performed cuts will always be better for your pocket book and for your trees.