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

Male or female Jatropha curcas from Brownsville TX
August 16, 2012 - How do know the sex of a young Jatropha C. plant? how many weeks before you can tell a boy/girl plant ?
view the full question and answer

Controlling Passionflora Incarnata propagation
March 20, 2012 - Would a cinderblock raised bed, 8 inches in height, be sufficient to contain the roots of passiflora incarnata and keep them from traveling to places where I don't want the vine? Are the roots deepe...
view the full question and answer

Need help fighting grass burs in La Grange, TX.
January 22, 2013 - I have 4 acres of wildflowers planted in my front yard. Unfortunately, grassburs have crept in & I need to control them with a pre-emergent. Will this keep the wildflowers from blooming? Also, would l...
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

Eliminating bluebonnets from lawn
December 05, 2009 - I need to know the best way to eliminate bluebonnets which are growing in my yard. My HOA is pursuing legal action against me to prevent me growing the plants. I can't afford to "resod" my yard. Ca...
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.
© 2015 Lady Bird Johnson Wildflower Center