Skip to main content

"Poisonous" does not mean deadly. Some manifestations of toxicity are subtle. The dose, as always, determines if a plant is safe source of nutrients or a toxic hazard.

Frequently (and not so frequently) Asked Questions

Simple keyword search (one or two words only)


BRIEF: Can black eyed susans hurt horses?

I was checking out the types of plants/ trees that could harm my horse. I wnated to plant some blackeyes Susans near my barn and wanted to make sure that they will not hurt my horse. Can you help me?


Updating that last answer, yes, at a high enough dose, Black-Eyed Susans have poisoned livestock, but the mechanism and toxin is unknown. Bummer, isn't it the symbol of the Preakness? Turner and Szczawinski, Common Poisonous Plants and Mushrooms of North America, p139, list the Cone Flower (Rudbeckia laciniata) as toxic, but I am not sure if its sister Black-Eyed Susan (Rudbeckia hirta) is, too. Sorry. It is in the same genus, though, so it bears further study.