Master Gardener: Setting the Record Straight to Poison Hemlock | Home & Garden

Brian Jervis Ask a master gardener

“I’ve seen people post about poison hemlock and see a lot of conflicting information. What do I need to know about poison hemlock in Tulsa?” — MW

You’re right. News sometimes seems to take on a life of its own, especially on social media, and poison hemlock seems to be one of those topics in Tulsa right now.

The first thing you should know is that poison hemlock is poisonous. Most of the toxins are found in the seed, lower stem, and roots. In any case, you should not take it as it can lead to respiratory paralysis, coma and death if not treated quickly.

It is a threat to livestock and wildlife. Pigs are most at risk, but so are cattle, horses, sheep and goats. Livestock should not graze infested pastures in early spring when this plant is an early, green forage crop. However, livestock are more likely to encounter poison hemlock in contaminated hay.

One of the challenges is that poison hemlock is similar to wild carrot (Queen Anne’s lace) and cow parsnip. Each of these plants produces small, white flowers, so it would be easy to confuse them from afar. One way to identify poison hemlock is that its stalk has purple spots. In contrast, the wild carrot has a hairy stalk and the cow parsnip has a ribbed stalk. None of their stems have a purple on them, so that’s a key identifier. Poison hemlock also has a cat urine odor that becomes apparent in the summer.

People also read…

  • Jenk’s teenager was killed in a crash in Tulsa County near Glenpool
  • Alo Turns Pro: Sooners Slugger Selects Vipers in Women’s Professional Fastpitch
  • Camper in tent next to victims recalls 1977 Oklahoma Girl Scout killings: ‘I had a lot of survivor guilt’
  • The proposed homeless ordinance “endangers progress,” the advocacy group tells Tulsa’s mayor and city councillors
  • Constitutional wear, straw buying and “ghost guns” contributing to Tulsa’s “wild, wild west” environment, police chief says
  • Watch now: Teaser trailer released for the series “Tulsa King” starring Sylvester Stallone
  • Monkeypox case confirmed in Oklahoma
  • Blake Shelton is joined by wife Gwen Stefani for Troy Aikman’s Highway to Henryetta
  • OU Journalism Graduate Megan Gold was crowned Miss Oklahoma 2022
  • A violent multi-vehicle crash disrupts traffic on US 169 in Owasso early Thursday
  • Cherokee Nation restores Oklahoma flag at locations
  • Gabe Glenn of the Sandites plans to follow her murdered mother’s wishes and play college baseball
  • According to a Commonwealth Fund study, Oklahoma ranks 50th for the COVID-19 response
  • Bynum admits to calling the city council chairwoman “so self-righteous” during the public session
  • The tide from Rock Creek rushes through the streets of Red Lodge

Poison hemlock prefers a moist, shady spot to grow and is often found along streams or ditches. From there it can spread to adjacent areas.

A challenge in eliminating this plant is that the seeds can remain viable in the soil for three years, so any attempt to control poison hemlock will be a multi-year process rather than a single and completed one. Full control is expected to take three to six years if a tiered approach is used.

Because some people get a rash from handling poison hemlock, you should always wear protective gear when handling this weed. A mask wouldn’t be a bad idea either.

Mowing is a good strategy because mowing stresses the plant and reduces its ability to absorb nutrients. Herbicides such as 2,4-D or dicamba are effective against poison hemlock. Since these seeds remain germinable in the soil for up to three years, this will also be a multi-year process.

So be aware, look for purple on the stems and mostly stay away. Much luck!

You can get answers to all of your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, stopping by our Diagnostic Center at 4116 E. 15th St., or emailing us at .

Watch the Tulsa King teaser from Paramount+

TULSA KING follows New York mob capo Dwight “The General” Manfredi (Sylvester Stallone) shortly after he’s released from prison after 25 years and summarily exiled by his boss to open a business in Tulsa, Okla With his best interests in mind, Dwight slowly builds a “crew” from a cast of unlikely characters to help him build a new criminal empire in a place that, to him, might as well be another planet. Other stars of the series are Andrea Savage (“I’m Sorry”), Martin Starr (“Silicon Valley”), Max Casella (“The Tender Bar”), Domenick Lombardozzi (“The Irishman”), Vincent Piazza (“Boardwalk Empire “). ), Jay Will (“The Marvelous Mrs. Maisel”), AC Peterson (“Superman & Lois”) with Garrett Hedlund (“The United States vs. Billie Holiday”).

The series is produced by Sheridan, Winter, Stallone, David C. Glasser, Ron Burkle, Bob Yari, David Hutkin and Allen Coulter. Braden Aftergood will also serve as executive producer.

Try it for free:

Follow Paramount+ for the latest news:





Leave a Comment