Perhaps we criticize this tree too much. Many of us still have a relatively good supply of parkland, back/frontyard space and a good population of native shade trees. Conversely, in the core of many big cities, nothing other than the Tree of Heaven will grow. This becomes the only natural shade that some people have. Thank goodness for its tenacity! It can drop its seed and grow out of any crack or crevice in the pavement of the asphalt jungle and it grows quickly enough to make a noticeable difference. Unfortunately though, as of 1996, even this tree has been dying in large numbers in Brooklyn and the experts are mystified!

History and name

     In this part of the country, everywhere one turns, one encounters the Tree of Heaven without possibly knowing its name and background. The tree is actually a native of Asia and northern Australia. It is listed as a serious weed in Australia and it was introduced to North America, via England, in the late 1800's. In those days people actually bought it for planting!

     The name Ailanthus is from the Moluccan name Aylanto literally meaning "Tree-of-Heaven" and, referring to the height of the tree, Altissima (Latin) means "very tall".

Characteristics

     The Tree grows very rapidly. It grows quicker, and persists more, than any other tree, even in poor soils and extremely polluted environments, and can exceed a height of 80 ft. and a diameter of 2 ft in about 10 years. In doing so it will often crowd out other tree species. Unfortunately old trees of this species are susceptible to wind and ice damage (with possible collateral damage to other structures). To eradicate the tree one has to eliminate the whole root system.

     Like the Ginkgo biloba tree, there are separate male and female trees. The leaves of both sexes - and the flowers of the male - are scentless on the tree but when crushed in ones hands will leave an unpleasant lingering odour on the skin. Examination of a single leaflet will disclose glands at the ends of the veins around the outer edge. The residue may cause dermatitis.

     Unlike the Ginkgo, the female tree is preferred as it produces inconspicuous clusters of tiny, odourless, yellow blossoms followed by attractive yellow/orange/red clusters of seeds and If the tree is not pollinated (no male trees around) the seeds will not develop into seedlings.

© W. Banner

Ailanthus in flower, July, 2001. Click on picture for larger image, "Back" to return.

     Personally I enjoy seeing this tree around Toronto. there are lots of them!

Trees dying in New York?