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

Identification of invasive plant
March 26, 2010 - I have found an invasive plant species in Martindale, Texas that I would like to identify for family members. It is taking over their pasture and is difficult to eliminate. It has not bloomed yet but...
view the full question and answer

Can a mustang grape and an oak coexist in Austin
November 04, 2009 - I have a healthy mustang grape vine growing on an oak in my yard. While the vine provides plenty of good food and a pleasant environment for many birds throughout the year, I feel it is overtaking the...
view the full question and answer

Plants for oak shade from Whitney TX
December 24, 2012 - I live in Whitney, Texas and have a number of beautiful Live Oak trees in a portion of my yard providing deep shade. Asian Jasmine grows in about 5 ft circle around them and then nothing! I have walk ...
view the full question and answer

Horsetail Rush invasive in Santa Monica CA
January 16, 2012 - Mr. Smarty Plants: I live about 3 miles from the beach in the Santa Monica area and have an 18inch deep planter area in my backyard that is adjacent to my garage. I like the look of horsetail rush. I...
view the full question and answer

Disposal of bulbs to control Arrowhead aquatic plant
August 29, 2006 - How can I kill Arrowhead permanently? I have sprayed repeated years with Roundup, Crossbow, etc., but the arrowhead comes back from the bulb the next year!
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