A PRUNE WITH A VIEW
Trimming trees is both an art and a science, not something that should be attempted by the untrained and unskilled By Normita Thongtham
Afriend of mine has a roadside tree in front of his house. It had become so dense that he could not see through it from his second-floor window. Last month he had it trimmed. There’s nothing earthshaking about that, I know. But what’s interesting is that after pruning, the tree retained its beautiful, rounded shape despite losing one-quarter of its branches. Now my friend can enjoy both the tree and the street view from his bedroom window through its now sparse branches. But he lives in the US, not Thailand, and the men who pruned his tree were Mexicans, not Thai.
Pruning should create well-proportioned and attractive trees, but try to have your tree pruned in Bangkok, or anywhere in Thailand, for that matter. All that will be left is a disfigured tree, its beautiful scaffold branches reduced to stubs, or worse, its canopy removed, leaving only the main trunk. One can see examples of this every day, be it along Bangkok’s streets or along provincial highways if you are travelling upcountry.
Thailand is not lacking in universities that teach agriculture and forestry. Don’t they include proper pruning in their curriculum, I wonder? If they do, I do not see any proof that what has been taught is actually being practised. Or is it too much to expect that those in charge of the maintenance of roadside trees have at least basic knowledge of how and when trees should be pruned?
It baffles me no end why the pruning of trees along provincial roads is done at the height of summer, and why they should be cut back to their main trunk. Removing the canopy deprives trees of their ability to produce food, leading to stress due to inadequate food supply. They are weakened and become susceptible to disease and insect attack. When they do recover, the new growth gives them a top-heavy look, with no branches to provide shade for motorists.
Those in charge of Bangkok’s trees perhaps belong to the same department, or came from the same school, for they are not any better. Only a few days ago, I was on Rama IV Road when I came upon workmen hacking trees. I understand that the branches should be removed to avoid contact with the utility cables above them. But these men should have been given training on how to properly remove branches while retaining the tree’s original shape and beauty.
Pruning is both an art and a science. To be able to prune properly, one must have an understanding of plant form and texture, as well as plants’ growth habits and how they respond when a stem is cut. When a tree is too high, its height can be reduced by cutting back the main trunk down to a strong lateral branch. And when the branches spread excessively, the outermost parts should be cut off to the next bud, leaving no stubs sticking out like a sore thumb.
To do pruning properly, one must have the right equipment. Hand shears, or hand pruners, are the most commonly used tool. These, however, can only cut limbs no bigger than 1.5cm thick. For bigger limbs, you will need a curved pruning saw. I also have a curved saw with a hook for pulling and removing cut-off branches; this is mounted on the end of a pole so I could cut off branches on tall trees while standing on the ground.
Another tool used to reach high branches from the ground are long-arm pruners mounted on a pole and operated by a rope, but again these can only cut limbs no bigger than 1.5cm thick.
Make sure that your tools are sharp and make clean cuts. A clean cut accelerates the formation of a callus for quick healing, thus reducing the chance of disease infection. Cut off the parts that must be pruned first, such as dead or dying parts and broken limbs. Branches that grow inward toward the centre of the canopy must also be removed.
A branch should be removed just beyond the branch collar, which is the swollen part that forms the base of the branch where it joins the tree. The branch collar is part of the trunk and not part of the branch, and it must remain intact. Do not cut into or damage it, for doing so may allow disease to infect the tree.
When a branch is too big, cut it in stages to prevent tearing of the bark and to remove the weight of the branch. First, make a cut about halfway deep on the underside of the branch, about 15cm away from the trunk. Next, make a cut on the top side at about 5cm from the first cut, cutting until the branch snaps. The remaining stub is then removed closer to the trunk outside the branch collar. If the tree were growing in the wild and the branch died back, it would be at this point that the tree would sever its connection with the branch.
Cutting just outside the branch collar leaves a little stub which soon heals, giving the tree a clean line. Long stubs will develop new growth, which will have to be pruned again in a year or two. If not, they will continue to grow without shape.
Trees beautify our surroundings but they pose a problem when they become too large. What we need are knowledgeable gardeners who are able to prune trees properly, like the ones who trimmed my friend’s tree. They have appropriate equipment and dispose of the branches after cutting them. If you are such a gardener, please come forward and introduce yourself; I know there are many homeowners out there who would like to know you.