Plants that kill: Be on the lookout for poison hemlock in hay

COLUMBUS, Ind. — Livestock farmers who use pastures should be on the lookout for poison hemlock — a toxic weed that can cause death and birth defects.

Robert Zupancic, grazing specialist at the Indiana Natural Resources Conservation Service, talked about the weed during a twilight pasture walk at Fleming Family Beef Farm.

“For the most part, animals won’t eat green poison hemlock unless they have nothing else to eat,” he said.

“The big danger is that it stays poisonous after it dies. If it’s in your hayfield and you bale it up, they can’t distinguish it from the rest of the hay. The two instances I know of hemlock poisoning in Indiana were exactly that — in a hay bale.”

It takes only two teaspoons of dried hemlock to kill a 400- to 500-pound calf, Zupancic said.

Poison hemlock is one of the first green plants to emerge in springtime. Most of it already is knee- to waist-high. It’s best to kill the plant early on.

“Once it’s waist-tall, it’s hard to kill even with herbicides,” Zupancic said. “It only lives for two years. Once it sets seed, it’s dead. If you can kill it before it sets seed you can control it.

“If you’re baling hay, making sure you don’t have any in your field.”

Symptoms of toxicity include nervousness, trembling and loss of coordination followed by depression, coma or death.

According to a publication by Purdue University, herbicides containing triclopyr or triclopyr plus 2,4-D are most effective in controlling poison hemlock in ditches, pastures and waste areas.

Learn more about poison hemlock at www.goo.gl/PPcy3o.