I have recently identified three large plants growing on a stream bed in my yard as water hemlock. From what I have read on-line, this is a very poisonous plant. Supposedly the stalks remain poisonous even when dead. My plants are quite bulky, and would fill at least a few garbage cans if cut down. Can you advise me on how to safely deal with these plants?



Waterhemlock is a very poisonous plant so every precaution should be taken when trying to control it.  If you remove the weed by digging it up you should take extra care to not cut or damage the plant because cutting it can release the poisonous juice into the soil or the water. 

For chemical control it is recommended that you use an herbicide that has glyphosate as an ingredient, Dicamba, 2, 4-D or MCPA.

When you are using any chemical herbicide, especially around water, you should read and follow all of the instructions on the label regarding the proper use and handling of that chemical. Some of the chemicals listed above may have restrictions about their use around water.  If you choose a chemical control make sure you read any restrictions before you purchase it.  Below I have included a link that includes information on pesticide use and safety. 


Posted on 1 Oct 2008

Heidi Wayman
Horticulture Intern, Salt Lake County

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