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?


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

Thursday - July 02, 2009

From: Vacaville, CA
Region: California
Topic: Invasive Plants, Problem Plants
Title: How can I eradicate Mexican Petunia from my garden in Vacaville CA?
Answered by: Jimmy Mills


Can you tell me the best way to eradicate the plant Ruellia, commonly known as Mexican Petunia, from my garden?


The Mexican Petunia (Ruellia brittonia {syn. R. Tweediana}) is a native of Mexico. It can be invasive and is listed as a Category 1 invasive species by the Florida Exotic Pest Plant Council. Its invasiveness is enhanced by its fast growth, prolific production of seeds, and an extensive root system.

Regarding getting it out of your garden, you don't want to spray herbicide in your garden, so one approach is to pull it out, and keep cutting back new sprouts; not necessarily an easy task. You also want to prevent reseeding by removing flowers after they fade so the seed pods won't develop, and also remove new seedlings as they appear. A chemical control method is to use glyphosphate.  Use this very carefully since it can also eliminate all of your other plants. Cut the Petunias down to the ground and apply the glyphosphate to the stumps of the stems. Be sure to follow the directions and warnings on the label.

For more help closer to home, I suggest that you contact the folks at University of California Cooperative Extension in Solano County.



More Problem Plants Questions

Shoots sprouting around base of liveoak tree
April 18, 2008 - I have a Live Oak that was planted in my yard about 15 years ago. In the last several years, small shoots have been sprouting up around the tree base, are getting more dense and spreading into the gr...
view the full question and answer

Dead, brown Habiturf lawn
July 07, 2015 - I planted Habiturf seeds last fall and had a good lawn all winter. Now the grass is brown and dead. Did it drown with all the rain we have had? If so, what should I do now? If not, what should I do...
view the full question and answer

Eradicating Cucurbita foetidissima (wild gourd) in California
August 23, 2013 - I live in San Diego County where the wild gourd/stink gourd roams freely and quickly. Any suggestions on how to eradicate. It is extremely invasive and nothing has worked! Thank you,
view the full question and answer

Problem with Chinese Pistache tree
September 01, 2014 - We have a gorgeous Chinese Pistache in our yard, about 25 feet tall. We bought it for its gorgeous fall color. The problem is that it has never turned color for us. All the other pistaches in the neig...
view the full question and answer

Can fibrous roots of Chasmanthium latifolium damage house foundation
May 03, 2013 - Dear Mr.Ms. S-P, Can the fibrous roots of inland sea oats cause foundation problems? I was digging around my foundation and found a root about 1" in diameter that I am afraid might be from sea oa...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2015 Lady Bird Johnson Wildflower Center