Winter 2001

by Joe Neumann

t’s chilly, damp, and dreary. We are tramping through the woods. What has drawn us out of our comfortable beds on this Sunday morning? If you could ask us, we would mutter: "Buckthorn." Buckthorn is a European shrub that can grow to the size of a small tree. In the case of buckthorn, green is not good. Because it is adapted to Europe’s climate, it leafs out early in the spring and remains green through November. This trait makes it an appealing landscape shrub. Its ability to spread into our native landscape makes it a pernicious weed.

Each of my companions has a saw. I am holding a tool of a different sort. It is a herbicide called Garlon. If you cut down a buckthorn and do not apply herbicide to the stump, it sprouts aggressively. We use the least persistent, most effective herbicide in as small amounts as possible. Forest Preserve District of Cook County Outreach Coordinator Jerry Sullivan reports that only 160 pounds a year of herbicide are put into the approximately 8,000 acres of natural lands under active management in the district. To apply herbicide on public property, you must pass a test of the Illinois Department of Agriculture. Garlon’s active ingredient is triclopyr. The Extension Toxicology Network provides detailed information on triclopyr, such as its average half-life (about 46 days depending on soil conditions).

Buckthorn is a more insidious killer than the Asian long-horned beetle. It shades out other plants. Even the mighty oak begins life as a lowly sprout. Nothing but bare soil lies beneath a large buckthorn.

On a damp day in the fall of 1990, I went on a tour of a forest preserve led by Ralph Thornton, then the land manager for the Forest Preserve District of Cook County. He told us that we would learn to hate buckthorn. Oh no, I thought, I may cut it if that is what needs to be done but I will never hate any part of nature. I still feel the same way. Unlike Ralph, I never had the depressing experience of witnessing the forest preserves being overrun.

A district ecologist once outlined to me the history of buckthorn in the Chicago region. It arrived in the 1950s. Its numbers expanded explosively in the 1970s. Now its population is leveling off. This last statement may seem strange until you wander an unmanaged forest preserve. Much of the site is sure to be so packed with buckthorn that no more can crowd in. Yet if population dynamics are largely responsible for slowing buckthorn’s expansion, district employees and volunteers can take some credit too. We have cleared it from thousands of acres of woods and prairies.

Today’s crew consists of seven volunteers and district naturalist Laura Ashman. We warm up on some small buckthorn and then shift to a substantial stand. Ellen has her hands full with a buckthorn with several twining trunks. She manages to saw through one but it is so entangled with its brethren that it cannot be removed. I hold the severed trunk out of the way while she applies her saw to another trunk.

A herbicider’s responsibilities call for him to move among the crew. His role expands from simply being a mechanical applicator to being an all-around helper always ready to lend a hand with the downing of a difficult buckthorn or some chitchat to provide relief from the work. I apply herbicide from a plastic container with a spout. The spout allows me to apply the herbicide directly to the cambium layer next to the bark where woody plants actively grow. This application minimizes the herbicide used and ensures that no nearby plants are inadvertently herbicided.

While I have been moving among the group, Chuck has been laboring on a gargantuan buckthorn. I take a turn with the saw. But brute force is not enough to topple this buckthorn. The weight of its trunk closes our cut. The saw blade binds. We abandon the base and direct our efforts against the upper limbs. We remove them all except one that arcs away from our cut. The weight of this limb will help keep our cut open. We set the saw at the base again. Chuck slices furiously into the wood. I push on the trunk, applying my muscle to keep the cut open. Finally the buckthorn topples with a thud.

"The townspeople can sleep in peace tonight," Chuck declares wearily. Not just yet. I carefully apply herbicide to the stump. Done. Rest easy, townspeople.