En Español

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

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

How toxic are wild cherries for horses?
June 11, 2009 - I purchased a beautiful piece of heaven in the rural suburbs. I have three horses and grow my own hay. Unfortunately, I have just learned the woods surrounding my field is lined with Black Walnut, Wil...
view the full question and answer

Tropical looking plants for pool area in California
November 14, 2008 - I am looking for small tropical looking plants, groundcover, and 2-small trees for around my pool. They have to be non-toxic to dogs,cats, and people. They can't attract bees/wasps, or have a root ...
view the full question and answer

Getting rid of wild plums (Prunus angustifolia)
July 28, 2008 - When I bought my land, there was a humongous thicket of wild plums (Prunus angustifolia) approx 10 ft high and covering 5-10 acres. I raise goats, and have known that wild plums (the leaves) can cause...
view the full question and answer

Smarty Plants on Texas cherry tomato
April 24, 2005 - We just bought 2 Texas cherry tomato plants at the plant sale. We have to container garden in a walled courtyard due to deer. (Would deer be attracted to the plants in a garden with herbs and high de...
view the full question and answer

Plant identification in Georgia
September 14, 2011 - I saw the same question that I was going to ask about the plant that folds its leaves at dusk, with sparse branches, rapid growth, small yellow flowers and long (whisker-like, but do not appear to be ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | JOBS | SITEMAP | STAFF INTRANET
© 2016 Lady Bird Johnson Wildflower Center