Be on the lookout for poison hemlock

Poison hemlock is continuing to show its invasive nature throughout Putnam County and Indiana. 

If you are not familiar with poison hemlock it is an invasive plant that can easily be mistaken for Queen Anne’s lace. 

Poison hemlock is a biennial plant that can grow up to 10 feet tall during its second year of life.  During year two, it will bloom. The flowers of poison hemlock are small and white and they are found in an umbrella-shaped cluster on top of the plant.  The leaves are fern-like. Blooming typically takes place during June and July. 

Based on the description above, you probably think this sounds a lot like Queen Anne’s lace or wild cow parsnip, which is correct.  Poison hemlock is commonly confused with those two plants.  You can tell it apart from those by looking at the stem.  The stem of poison hemlock will have purple spots on it.

It is important to know how to identify poison hemlock because it is highly poisonous and can be fatal to humans and livestock.  Poison hemlock easily invades areas around roads, streams, trails, ditches, forest edges, and waste areas.  It is well established and widely distributed throughout Indiana.

If you have poison hemlock on your property, it is important to understand how you can control it.  Begin by mowing infested areas before the seeds mature.  For small infestations, you can pull up plants and dispose of them in a trash bag.  If you do this process, remember to use gloves and other personal protective equipment to prevent your skin from coming in contact with the plant.  This would also include covering your eyes with goggles/glasses. 

For large infestations, you may decide to spot treat with herbicides. As with any herbicide use, you need to always read and follow all label instructions.  Ideally, herbicide application should be performed while the plant is actively growing and before flowering. 

For more information about how to identify and control poison hemlock, download Poison Hemlock, FNR-437-W, from Purdue Extension and Southern Indiana Cooperative Weed Management Area at <https://www.extension.purdue.edu/extmedia/fnr/fnr-437-w.pdf>.  If you are unable to download the publication, please contact Purdue Extension at 765-653-8411 to obtain a copy.

Visit our homepage at www.extension.purdue.edu/putnam or you can contact the local Purdue Extension Office by calling 765.653.8411 for more information regarding this week’s column topic or to RSVP for upcoming events. It is always best to call first to assure items are ready when you arrive and to RSVP for programs. While many publications are free, some do have a fee. Purdue University is an equal access/equal opportunity institution. All times listed are Eastern Time.

Upcoming Events:           

May 21 – ServSafe Food Manager Day Class & Examination, Putnam County Fairgrounds, register at https://cvent.me/aEGqDV

May 26 - Extension Office closed for Memorial Day

May 28-31 – 4-H Camp