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 Butterfly Gardens Questions

Amending soil for butterfly garden in Houston
April 01, 2013 - My girl scout troop will be planting a butterfly garden at a middle school in Houston. In researching plants to use, we have come across some such as echinacea, rose vervain, galliarda and Texas gay...
view the full question and answer

Making a pollinator garden
August 11, 2014 - Hello, I have a ditch right by my house and I want to turn it into a pollinator garden using native plants. My problem is, right now it's so full of weeds that we have to mow those down so soon. For ...
view the full question and answer

Native annuals for pollinators in King County, Washington
February 06, 2014 - I live in King County, Washington State, and I have a plot in a community garden. Rather than plant food, I'd like to attract pollinators. I need to use native annuals rather than perennials as the c...
view the full question and answer

Plants for attracting butterflies in Austin
April 28, 2012 - My 9 year-old son is interested in finding butterfly eggs this Spring. His 3rd grade class is studying butterflies right now. I found a Wildflower Center article that lists several plants butterflie...
view the full question and answer

Butterfly/hummingbird garden plants for Hill Country, TX
February 04, 2011 - What drought resistant plants would you recommend for a Hill Country butterfly/hummingbird garden that receives at least a half day of sun? It has afternoon exposure.
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 | STAFF
© 2015 Lady Bird Johnson Wildflower Center