The Tree of Heaven (Invasive Tree)
I don’t normally worry too much about invasive plants and noxious weeds. Most of these plants can coexist in a healthy ecosystem. However, every site is different. On my site, I am taking a stand against ailanthus altissima, which is tree of heaven, also known as stink tree, ghetto palm, or tree of hell. It is a fast growing pioneer tree from China. It can reach heights of 80 feet, and I’ve seen them grow to fifteen feet in just a couple of years. These would be great characteristics if the tree didn’t produce ailanthone, a chemical that inhibits the growth of plants around them. This can reduce the diversity of a site.
The tree of heaven looks awfully similar to the black walnut tree, staghorn sumac, hickory, and ash. Its roots can be very invasive doing damage to underground structures. It has very soft flexible wood that breaks relatively easy, but if cut and dried properly hardens, and can be used as firewood. It also produces a smell reminiscent of cat urine.
Despite the fact that the tree is not particularly useful to me at this time, doesn’t mean that it is without use. Being a fast growing pioneer species, it is creating fast carbon pathways. If dried properly, it can produce viable firewood. Using ailanthus for firewood would be very sustainable, as you could burn wood that is quickly renewable. They also readily regrow from their stumps, so coppicing could be done. This suckering habit also makes it difficult to eradicate this tree.
In China, the tree of heaven has been used to cure many ailments ranging from mental illness to baldness. Today, it is still used today in traditional Chinese medicine as an astringent. The most common use for the tree both in China and abroad is as a host plant for the ailanthus silkmoth, a moth used for silk production.
Ailanthus’ most beneficial use in my opinion is as pioneer species to reforest severely damaged land with very acidic soil, and or contaminated land as it can grow in soil as acidic as 4.1 pH.
The most effective control methods involve physical and chemical treatment. This involves cutting down the trees then applying an herbicide to the stump. I will not use an herbicide, so I cut and drop the trees, and pull the small seedlings. I will have to cut and cut and cut and cut, but the roots will eventually run out of gas. This is more time consuming, but I will try to find a use for the wood in the meantime to try to turn the problem into the solution.