Are all Milkweeds dangerous to livestock?

Asked January 28, 2020, 10:33 AM EST

We’re having a discussion about Milkweed in our gardening group in South Deschutes. A member is concerned about us growing Milkweed for Monarchs as she fears it is fatal to cattle and Sheep and will spread. True? And does this apply to all Milkweed?

Deschutes County Oregon

1 Response

Hi, Yes all milkweeds contain toxins that can be poisonous to livestock, so caution should be used in where it is planted. The two types of milkweed that are native to Central Oregon is Showy Milkweed and Narrow-leaf Milkweed. It is important to keep pastures and hay free from milkweed. I am not aware of any sites in Central Oregon where it has spread vigorously. It may be worth calling the local Weed Vegetation Specialist to see if he has additional information on its spread. You can call me at the number below and I can give you his contact information . Here are some websites that explain it further: https://csuvth.colostate.edu/poisonous_plants/Plants/Details/11 Milkweed is unpalatable to horses, see more about that here:
https://aces.nmsu.edu/pubs/_b/B709/ Here is some additional information : https://alfalfa.ucdavis.edu/-files/pdf/LivestockPoisoningPlantsNov2010.pdf Thanks, Amy Jo