Knowledgebase

Poison Hemlock #865189

Asked April 19, 2024, 9:45 PM EDT

Hello, How do I get rid of Poison Hemlock once and for all? I have combatted this for 3 years. I live in Metolius, Oregon. I remove it but it comes back. The neighbors and alleys have it too. Thank you, Cynthia Short

Jefferson County Oregon

Expert Response

Hi Cynthia,

Do you have a photo of the hemlock? Would like to confirm that is is poison hemlock (wear gloves, long sleeves, pants etc when around the plant to protect your skin from sap).  Is it growing in an irrigation ditch/pond? 

Please feel free to contact me directly.

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook


An Ask Extension Expert Replied April 26, 2024, 8:38 PM EDT
Hi Lisa,
Here are 2 pictures.  It is all over the town of Metolius.  I think it possibly came from the irrigation water.

Thank you,
Cynthia Short

On Fri, Apr 26, 2024, 5:38 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied April 30, 2024, 9:50 PM EDT

Hi Cynthia,

Thank you for these photos.  I zoomed in but couldn't tell if there were purple spots/blotches on the stems which is characteristic of poison hemlock.  Apologies for not being specific on getting photos of stems as well.  Can you confirm that there are purple blotches/speckles on the stems (at least on more mature plants)?  I'm including a link that shows what this might look like: 

https://ipm.ucanr.edu/PMG/PESTNOTES/pn74162.html

Thanks,

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook



An Ask Extension Expert Replied May 02, 2024, 7:40 PM EDT
Hello, 
Here are more pictures.  There aren't any black spots on the stem.
Thank you for your help.
Sindi

On Thu, May 2, 2024, 4:40 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 06, 2024, 2:41 PM EDT

Hi Cynthia, 

Thanks for the additional photos. The last photo (ending in 074)  clearly shows hairy stems. Poison hemlock does not have hairs on the stems.  I am wondering if this is a type of  Chervil or Queen Anne's Lace. 

Would there be anyway you could bring in a sample for us to take a look at further? The address is below.

Thank you.

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook


 

An Ask Extension Expert Replied May 08, 2024, 12:09 PM EDT
Lisa,

Yes, I will do that.  What are your hoursThank you,
Cynthia

On Wed, May 8, 2024 at 9:09 AM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied May 08, 2024, 7:32 PM EDT

Hi Cynthia, 

Our office hours are 8:00AM-5:00PM, Monday-Friday.  See address below. (Look for parking lot J).  If I'm not here, the plant can be left at the front desk. Let our office staff know it is for me.   If you can find a plant in bloom by any chance that would be great.  Include the root if possible. Wear gloves/long sleeves as a precaution when pulling up plant. 

Thank you!

Lisa

Lisa Cowan

Outreach Program Coordinator – Community Horticulture Program

Oregon State University

OSU Extension Service – Deschutes, Crook, Jefferson Counties

3800 SW Airport Way, Bldg #4

Redmond, OR 97756

Tel.:<personal data hidden> (direct line) I<personal data hidden> (x79590 - main line)

Website | Facebook

An Ask Extension Expert Replied May 09, 2024, 7:26 PM EDT

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