Poison hemlock

Asked June 21, 2013, 4:51 AM EDT

We live on a 9 acre farm and one corner is covered in a plant from the wild parsley family. Someone told us it is poison hemlock, another told us it is Queen Anne's lace. I have tried to look up the difference but can't seem to tell them apart so we want to just kill it all. What is the safest way to kill it without any risk of harm to the horses? (It's fenced off now)

Island County Washington

1 Response

Good morning. With regard to identifying the plant, one of us here on eXtension.org should be able to name it if you sent some photos of the plant, especially if it is blooming right now. The chemicals that will kill it are herbicides and are specifically toxic to plants and generally not toxic to your horses. Typically, the recommendation is to spray the weeds before they start blooming and setting seed in order to achieve the best control, but you can spray them now and get adequate control. If the weeds are in a grass pasture area, then use a product containing 2,4-D (such as Weedar) which will only kill the broad-leaf weeds and not the grass. You can also spray a product containing glyphosate (such as Roundup) but that herbicide will kill all plants. Also, it is recommended that you wait until the weeds start browning before allowing horses to graze in that area. 2,4-D treatment actually makes the plants taste better to horses and encourages them to nibble on the treated weeds which is definitely NOT what you want. You are welcome to send photos of your weeds if you want to know what you have. Good luck with the weed spraying!