Poison Hemlock


Among Northeastern Illinois’ weed list is a very dangerous plant called ‘Poison Hemlock’  (Conium maculatum) and should be removed very carefully from your landscaping promptly!

(Image from www.illinoiswildflowers.org.)

On this plant of the carrot family, you will notice that the flowers have 5 petals on each set.  The typical cluster is roughly 2-2.5″ across distinguishing it from Queen Anne’s Lace.  Also, Queen Anne’s lace has one red floret in the center of its flower cluster, poison hemlock does not (as seen above.)

(Image from phytophactor.fieldofscience.com.)

You will notice that the leaves of the Poison Hemlock plant look similar to the carrot.  The smooth stem is stout, has a ridged appearance and is marked with purple spots. The stem is hollow. Leaves are large and very ferny in appearance. (www.mortonarb.org)

(Image from www.ohioline.osu.edu)

Management: Plants can be cut down or dug out. This should be done before the plants go to seed and is most easily done when plants are small. Cover your skin during this process. Do NOT burn the plants. In spring, small, actively growing plants may be treated with an herbicide containing glyphosate.  (Please be very careful when handling glyphosate!) (www.mortonarb.org)


For more information, please visit the Morton Arboretum website, or visit http://hyg.ipm.illinois.edu/article.php?id=380


Thank you for reading our blog post! Please feel free to share your comments with us. All content is copyrighted by Nelson Tree Service- 'The Cure for Trees', Inc. unless otherwise noted. All Rights Reserved. We are part of the Amazon Affiliates & CJ Affiliates programs and may receive a monetary allowance for any products purchased by linking to them.

Be Sociable, Share!

Leave a Reply

Your email address will not be published. Required fields are marked *