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Why Topping is the Lowest of Practices
Let’s get it straight: topping is not normal, it’s
not beautiful, it’s not the right thing to do. It’s
also illegal according to city ordinance. If you see it, report
it to SF DPW Bureau of Urban Forestry, 641-2676.
The sycamore trees at City Hall and at Golden Gate Park’s
bandshell are not topped, they’re pollarded. Pollarding
is a specific form of pruning that originated with French
peasantry centuries ago. Before the advent of central heating,
peasants were allowed to cut firewood from the trees on the
lord’s land. Through trial and error, the freezing serfs
discovered that they could scalp a sycamore tree within an
inch of its life and it would come back in the spring. Other
trees died from such treatment. If you’re interested
in the special effect of pollarding, consult an arborist first.
Why is topping bad for a tree? First, remember what trees
"eat". Trees "eat" light. Their leaves
take in light and transfer it into the energy it needs to
live. The larger a tree is, the more leaves it needs to live.
So when you top a tree, you take away its ability to eat.
The tree has to live off its stored energy, and go to Plan
B. Plan B is to sprout from all its little dormant buds lying
under the bark all over the trunk and what is left of the
branches. Sprouts pop up in little clusters and point in all
directions. This is why many people erroneously believe that
topping "rejuvenates" a tree, because they see all
the shoots. In fact, what they are looking at is desperation.
It costs the tree a lot of energy to put out all these shoots,
energy that it should be using to fight off pests or heal
wounds. That’s why many topped trees are susceptible
to bugs and diseases, and some just die outright.
If you top the tree because you think it’s too big,
you will have more work next year if it survives, since each
cut will cause 3 or 4 or 10 more sprouts to come out. Each branch will try to grow as tall as the tree is genetically supposed to grow. (This is why it's better to do your homework and plant the right size tree in the right place.) Sprouts that turn into branches
are poorly attached and can easily break. This makes for a
more hazardous tree. A properly pruned tree will not need
pruning as often, saving you money, and will be safer.
A topped tree can possibly be rehabilitated. There is a better
chance if it’s a younger tree. But it takes time, and the tree may look awkward during the process.
How do you learn the right way to prune? Take one of our
periodic free pruning workshops. Take a class at City College
or Merritt. Really look at the way a tree grows. Watch one
tree for years, if you can. Big branches taper to smaller
branches. Buds break into shoots. Your cuts should go with
the pattern, not against it. Your handiwork should be nearly
invisible, like a good haircut.
Approach both people and trees with the proper respect. Be
considerate with your cuts and your words, so we may all continue
growing in the direction we were meant to.
See more about topping at this excellent link:
http://www.urbantree.org/topping.asp
Download PDF files in English and Spanish about topping from
this site:
http://www.arborday.org/programs/treecitybulletins.html
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