En EspaŅol

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.
Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Tuesday - November 01, 2011

From: Austin, TX
Region: Southwest
Topic: Butterfly Gardens, Poisonous Plants
Title: How toxic are milkweed (Asclepias spp.)?
Answered by: Nan Hampton

QUESTION:

We are considering a monarch waystation for our local elementary and are concerned about milkweed toxicity. Would it be safe to plant it in reach of children?

ANSWER:

The Poisonous Plants of North Carolina database says that all parts of Asclepias species are poisonous, but are "Toxic only if large quantities are eaten."  The Toxic Plant Database of Purdue University Veterinary School agrees with this assessment.  Moreover, the plants are generally unpalatable.  Grazing animals don't readily eat them unless they are confined in a pasture with large numbers of plants or the plants have been included in hay given to them.  The compounds that are toxic in the milkweeds are cardiac glycosides.  The monarch larvae eating the plants sequester these toxins in their exoskeletons where they remain even after they metamorphose into butterflies.  Not only do they make the butterflies taste bad, but the glycosides have an emetic effect that causes a predator, such as a bird, to vomit.  Predators apparently remember and associate the butterflies with the unpleasant taste and learn to avoid eating the monarch.

According to the Botanical Dermatology Database, several species of the family [e.g.,  Asclepias viridis (Green antelopehorn)] can cause dermatitis from the milky sap so you should probably protect the plants to keep them from being broken and exuding the sap.

Since milkweeds are unpalatable and they don't contain attractive fruits that might tempt the children to eat them, I don't think that you should be overly concerned about including them in your butterfly garden. 

 

More Poisonous Plants Questions

Plants Toxic to Horses
October 26, 2013 - I want to put planters on the front of my horse barn, which is also in the front field, so the horses could eat what is in it if they want to. I am looking to put a miniature pine tree in the planter....
view the full question and answer

When will angels trumpet bloom in Vero Beach, FL?
May 31, 2009 - At what age or height will my angel's trumpet be able to produce flowers?
view the full question and answer

Is Asclepias incarnata poisonous to dogs?
June 13, 2012 - Is Asclepias incarnata safe in a farm/yard with plenty of dogs running around? What happens if a dog eats the leaves or seeds or pods? Is eating any of these fatal to dogs?
view the full question and answer

Fast-growing tree for horse arena in Southern California
July 06, 2011 - I live in Trabuco Canyon, CA, and we just lost an old Sycamore in our horse arena. I would like to replace it with some thing that is fast growing, and will be able to withstand life around horses, o...
view the full question and answer

Information about Rosa acicularis
March 07, 2008 - Hi: At your site under "Benefit" it is mentioned that the seeds, leaves bark and twigs of Rosa acicularis Lindl. can be fatally poisonous to humans and animals. None of my past or present studies h...
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center