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

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

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

The plant that likely killed 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 over the past 15 years, according to the state Department of Natural Resources.

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

“This species is famous for its poisonous sap,” Gardner said. “It was used to exterminate people in ancient times. It has alkaloids that, if ingested, can cause death.”

What is poison hemlock?

Poison hemlock is not native to the area but is native to Eurasia, Gardner said.

“It was introduced into North America as an ornamental plant in the 19th century; the first reports of its escape in Ohio date back to 1860,” he said.

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

The plant belongs to the carrot family and is biennial, meaning its growth cycle lasts 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 leaves that are very deep inside, like a fern,” Gardner said. “Poison hemlock has smooth purple dots all over the stem.”

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

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

Symptoms of poison hemlock ingestion

Unlike other poisonous plants, hemlock doesn’t cause severe blistering of the skin when someone touches it. It can only cause problems if it’s ingested or if a person has an open wound and touches it, according to Gardner.

According to the Cleveland Clinic, multiple symptoms can occur immediately after ingesting the plant, including vomiting, muscle weakness, tachycardia, seizures and high blood pressure.

In more severe cases, it can cause slow heart rate, 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 cut it or burn it, it can become an aerosol and come out of your mouth and nose,” he said. “If it splashes in your eyes, you can have some reaction around them.”

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

“If it’s already in flower, it’s pretty much taken all the energy out of the roots and put it into producing fruit,” he said. “You can cut it off at the base, put all the protection on it and bag it (the plants) up and throw them away.”

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