Poisonous Plants

Many property owners are concerned about poisonous plants that might harm livestock.  
There are two important questions to ask:

• What plant is it?

• How much is eaten?

Some plants, such as water hemlock, are toxic in small amounts.  For other plants, such as ground cherry, a large amount must be eaten before problems occur.

Animals avoid most toxic plants if adequate forage is available. If you see increasing populations of toxic plants or weeds in your pasture, evaluate your grazing program.  Over-grazing often contributes to the problem.

Toxic plants are more likely to be a problem during drought when there is less high quality, succulent forage available.

Links

Guide to Poisonous Plants by Dr. Tony Knight, Colorado State University

Other Poisonous Plant sites

• USDA/ARS Poisonous Plants Research Laboratory, Logan, Utah
• Cornell University Poisonous Plants Page
• Canadian Poisonous Plants Information System
• Guide to Poisonous Plants - Colorado State University
• Indiana plants poisonous to livestock and pets
• Plants toxic to animals [University of Illinois]
• Poisonous Plants of Veterinary Importance - University of Pennsylvania