Gardening: Invasive tree “unheavenly,” fast-growing
Spotted lantern flies feed on Tree of Heaven near Winchester.
Tree of Heaven leaf with notches in the leaflets noted with a red arrow. Photo/Tim Ohlwiler
By Tom Baughn Fauquier Master Gardner
While the Ailanthus altissima is commonly known as the “Tree of Heaven” in Asia, it is anything but divine in gardens and woods of Virginia.
The highly-invasive species desperately needs to be on everyone’s watch list. This year demonstrated how badly it spreads. The winged seeds from a single tree can show up miles away, and nearer to the tree you will see hundreds of sprouts in a single season.
But wait, it gets worse. The Ailanthus is also the favorite host of a new insect pest, the spotted lanternfly. The potted lantern fly was found in the Winchester area last winter and probably will show up in in other parts of the state. Believed to have originated in China, it was found in Pennsylvania a few years ago.
The spotted lantern fly has been documented as a pest on grapes, peaches and apples, as well as many of our forest trees. Please, let your local Virginia Cooperative Extension office know if you spot this insect.
Identifying the Tree of Heaven is fairly easy, although its compound leaf is similar to the black walnut tree and sumac. Sumac is easily ruled out as it bears a cluster of reddish-brown berries the size of a fist. The black walnut is not as easily ruled out, but the Ailanthus leaf has a small lobe or tooth on both sides, at the base of its leaf. (See illustration.) The main stem of the young Ailanthus also has a distinctive yellow or light-green color, compared to dark-green to brown stem for the black walnut.
Growing 3 to 6 feet in the first year, it reaches seed-producing size quickly. A mature tree can produce more than 300,000 seeds a year. Unfortunately, this proliferation of seeds more than compensates for a disadvantageous characteristic of the Ailanthus, its short life span and soft wood. The tree also freely produces suckers — below-ground lateral growths that sprout new vertical stems several feet from the parent. If you pull the sprout in its first season, ideally less a foot in height, it is relatively easy to control. Be careful to pull gently and gradually, instead of jerking quickly, to get all or most of the root.
If it can be done without harming desired plants, an herbicide that goes to the root is also recommended as a follow up. Please, help us control this hellish invader.