Thursday, August 14, 2008

Heavenly Invader

Now that I have a yard to tend, I've suddenly noticed a new tree that is shooting up everywhere in Connecticut: the "tree of heaven" (Ailanthus altissima). It is similar in appearance to the staghorn sumac, which is native to the northeast, so this may be why I didn't notice it until just now. The other day I thought back to when I was growing up. The trees in our yard were mostly pine, maple, chestnut. Twenty years ago, maybe even ten years ago, maple trees were the most prolific Connecticut tree (going by my memory). Now where I live is surrounded by the tree of heaven.

The most noticeable thing about this tree is that it grows like a weed. It can release up to 325,000 seeds per year. If you cut it down to a stump, the stump will sprout numerous shoots. If you pull it out with the roots, any tiny little root fragment left in the ground will start growing a new tree. It ought to be called the hydra tree.

I've been somewhat casually trying to remove the saplings growing along my property line. There's a slender stump that has maybe half a dozen new shoots growing on it every other month. The good news is that they are easily broken in half. But they will keep coming back for all of eternity. They grow fast, too, and can get as tall as 80 feet (or more) in a relatively short span of time.

Full-grown, it does make for a nice shade tree. But it really is a destructive weed of a tree. The roots can damage sewers and foundations. It produces a type of toxin that prevents other types of plants from growing, and it can quickly crowd out any other type of tree. The maple tree has met its match.

In researching the tree of heaven, I learned a couple of interesting things about it. First, it is native to central China (known in Mandarin as chouchun). It was brought to Philadelphia in 1784 by a gardener, and by 1840 was available through nurseries. Now it is somewhat universally regarded as a pest, although it is the title "character" of A Tree Grows in Brooklyn.

1 comment:

Peter said...

One feature of the ailanthus is that it can grow in hostile environments where other trees cannot. A demolition site that's far more building debris than dirt? It will grow. An exhaust-choked highway median? Same thing. In a strange way I find that admirable.