Radio You Need To Know
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Poisonous hemlock now found in all 88 Ohio counties. Here’s how to get rid of it

White flowers clustered together
Ohio Department of Natural Recources
Poison hemlock can be identified by its white flowers and purple dotted stem.

The plant that likely killed the Greek Philosopher Socrates may be blooming in your garden or along your favorite hiking trail.

Poison hemlock has now been detected in all 88 Ohio counties and has become more abundant in the past fifteen years, according to the state’s Department of Natural Resources.

The plant is deadly if ingested, said Rick Gardner, chief botanist at the Ohio Department of Natural Resources.

“This species is famous because of its poisonous sap,” Gardner said. “It was used for extermination, terminating people back in ancient times. It has alkaloids in it that if it’s ingested can cause death.”

What is poison hemlock?

Poison hemlock is not native to the area. It’s originally from Eurasia, Gardner said.

“It was introduced to North America as an ornamental plant in the 1800s — first reports of it escaping in Ohio was in 1860,” he said.

The plant grows on roadsides, fields, forests and in any areas where soil has been disturbed, such as around buildings or ditches.

The plant is a member of the carrot family and is biennial, which means its growing cycle takes two years. The first year it is just a rosette of leaves. In the second year, it flowers and spreads its seeds before dying.

How to identify poison hemlock

“It has what are called clusters of flowers and has very deep inside leaves, like a fern leaf,” Gardner said. “The poison hemlock has smooth, purple dots throughout the stem.”

The flowers are small and white, and the plant is identifiable because it can grow up to ten feet tall.

“It blooms typically around mid-May and then into June or even into early July,” Gardner said, “especially in the northern part of the state.”

Symptoms of ingesting poison hemlock

Unlike other poisonous plants, hemlock does not cause severe blistering of the skin when someone touches it. It can only cause issues if ingested or if a person has an open cut and touches it, according to Gardner.

There are multiple symptoms that can occur right after eating the plant, according to the Cleveland Clinic. These symptoms include vomiting, muscle weakness, rapid heartbeat, seizures and high blood pressure.

In more serious cases, it can cause a slow heartbeat, low blood pressure, muscle paralysis and kidney failure.

How to get rid of poison hemlock

There are safe and unsafe ways to eradicate poison hemlock, Gardner said.

“If you chop or burn it, it can become an aerosol and come through your mouth and nose,” he said. “If it splashes into your eyes, you can get some reaction around your eyes.”

The best way to take care of this plant is to treat it with herbicide when it’s not in bloom, so as to not cause any reaction to the pollen and seeds it releases, according to Gardner.

“If it’s already in flower, it pretty much has taken all the energy out of the roots and put it into producing the fruit,” he said. “You can cut it at the base, wear all the protection and bag [the plants] and put them in the trash.”

Gardner suggests wearing gloves, long sleeves and eye protection when handling poison hemlock.

Des Torres is an intern at Ideastream Public Media.