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

Sunday - March 24, 2013

From: St. Augustine, FL
Region: Southeast
Topic: Invasive Plants, Non-Natives, Herbs/Forbs, Trees
Title: Will non-native and invasive Mexican petunias grow under oak trees from St. Augustine FL
Answered by: Barbara Medford

QUESTION:

Will Mexican Petunias grow under an Oak tree?

ANSWER:

The Lady Bird Johnson Wildflower Center, home of Mr. Smarty Plants. recommends only plants native not only to North America (excluding Mexico) but to those areas in which the plants will be grown; in your case St. Johns County on the northeastern Florida coast.  Ruellia brittonia (Mexican petunia) is native to, well, Mexico. Since you live in Florida you should read the following two articles:

Floridata Ruellia brittoniana, see the Warning at the bottom of the article.

Florida Invasive Plant Education

We just learned that petunias are considered to exhibit allelopathy, as well as oaks. Allelopathy is the release of chemicals by the plant which discourages competition from other plants. Maybe the oak and petunia would duke it out, but we are rooting for the tree.

Please note that it is difficult to impossible to grow anything under any tree, including grass, because of the needs of the tree roots for moisture and nutrients from the soil and because of the shade from the tree. Here in Texas, we would vote for the trees and spread mulch under the shade of the tree. See our How-To Article Under Cover with Mulch.

 

More Non-Natives Questions

Rose bush varieties and time to plant from Hutto TX
October 31, 2013 - What rose bush varieties are recommended for the Hutto Texas area and what time of year is the best time to plant into ground? Thank you.
view the full question and answer

Question about non-native blue potato tree
July 08, 2008 - I have a blue potato tree that I planted last summer, the top looks dead but isn't, the bottom has grown into a bush, help what can I do?
view the full question and answer

Elimination of non-native English ivy in Maryland
March 11, 2009 - I have Old English Ivy sprouting up throughout my side yard. What can I do to get rid of it? Would putting lime down help or Crabgrass control? What would you suggest and the easier the better as I...
view the full question and answer

Request for native grasses from Hillsboro TX
August 04, 2012 - P.S. I forgot to mention one very important fact: my neighbor specifically asked for "native grass" recommendations. He thought he was getting a native grass recommendation.
view the full question and answer

Non-native. Why are my potted Royal Empress trees dying?
June 22, 2009 - I have purchased several Royal Empress trees over the past two years. Why won't they grow? Some sprouted leaves and then died while in the pots I planted them in. While others, that are 2 years old ...
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