Blue River

Invasive Species Control

Read about Marg Meyer's battle against the not-so-heavenly Tree-of-heaven.


Though its name makes it sound heavenly, Tree-of-Heaven is no angel. Learn more about this invasive pest.

The following was written by Marg Meyer of Corydon, Indiana.

My sister Marydee and I inherited about 130 acres of forestland in 1998 when our father died. He set such a fine example of good forest husbandry that we were at a loss of what to do to keep up his efforts. As the quintessential German, he wasn't a good teacher but an excellent doer. So, we finally got a toehold on the proactive foresting other than the every decade or so timber cut. Our district forester, Mike Coggeshall, during a required tour of the trees, pointed out several Ailanthus altissima trees, better known as tree-of-heaven. When he got to the part about the trees with their rapid growth choking out the native hardwoods, he got our attention. With advice from him and the Nature Conservancy, we started out to "control" this invader. Mike said that this would not be just a one year effort.

I ordered a 2.5 gallon container of Pathfinder II. Mike had provided a topographical map with areas shaded where he had found Ailanthus. My Great Dane, Nessie, and I spent that winter cruising the woods and marking Ailanthus with colored tape. The bark looks much like young poplar bark, and the leaves look pretty similar to walnut leaves. If you're looking for Ailanthus, crush one of the leaves or take a pocket knife and cut a bit into the bark. You'll know then that, if you smell rancid peanut butter, you've got yourself a tree-of-heaven.

The first year sissy and I started out right before frost with two garden sprayers each full of Pathfinder II. I'm sure we looked like Martians in hazmat suits--hats, boots, rubber gloves, masks. We must have worked for three or four hours each going from spot to spot spraying around the bark from knee height down to the base. It took the entire container of herbicide. The ensuing winter and early spring was spent with Nessie walking through the trees, looking for baby invaders, which sprout from the extensive Ailanthus root system. Late fall we both were out spraying again using only two-thirds of a container. The last two years, the invasion has lessened so much that I've sprayed the trees by myself, using much less herbicide.

I felt we were ahead of the game--until this summer. We had to log out the ash trees while they still had some value as another invasive, the emerald ash borer, had reached our woods. We know that this harvest will stir up more Ailanthus from dormant seeds.

My heart breaks when I drive around Harrison County and see all of the Ailanthus flourishing. I can't help but see them. The Farm Services Agency has some funds to help out with the herbicide purchase. I've come out about even in that area--my cost is in time to find and spray this nasty tree. Our forest is in good shape and getting better. I know now that this sure doesn't happen overnight, but it is well worth the investment. My niece and nephews will thank us someday.

Ailanthus altissima, or tree-of-heaven, has been given the invasive rank, HIGH, by the Indiana Invasive Species Council. It is an invasive tree that threatens the long-term health and regeneration of our oak forest in Harrison County and Southern Indiana. It can be found almost anywhere growing in your yard, along roadways, urban areas, and our natural areas. If you need assistance in identifying tree-of-heaven or technical advice, contact Beth Mizell.


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