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

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 Invasive Plants Questions

Have invasive plants no useful purpose from Anchorage AK
September 03, 2011 - Does the definition of invasive plants include that the plant has no useful purpose? Thanks.
view the full question and answer

Grass for Seattle Arboretum
May 20, 2012 - I am writing to you on behalf of the Arboretum at South Seattle Community College Arboretum. I am interested in Panicum virgatum Switch Grass as a plant for a very heavy clay garden in our Arboretum a...
view the full question and answer

Wildflower Center work on non-native, invasive Bastard Cabbage from Austin
March 20, 2014 - Still have cabbage weeds that infiltrated Austin awhile back. How did Wildflower Center resolve it?
view the full question and answer

Invasiveness of wild petunia in Austin
June 15, 2008 - Is the wild petunia in the data base as invasive/aggressive as the more common ruellia? In other words, will it pop up everywhere? Ruellia nudiflora (Engelm. & Gray) Urban Common wild petunia, Vi...
view the full question and answer

Non-native mimosa failing to bloom in Leitchfield KY
October 29, 2011 - I have a medium size mimosa tree here in KY that usually blooms beautifully; it did not bloom at all this year. It leafed out well, needs a few dead limbs pruned, but seems otherwise healthy. Please t...
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