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

Tuesday - July 17, 2007

From: Paris, France
Region: Other
Topic: Non-Natives
Title: Care of Rio Grande Wild Petunia
Answered by: Barbara Medford and Joe Marcus

QUESTION:

I have bought the Rio Grande Wild Petunia, Ruellia davisiorum. How should I look after it?

ANSWER:

The really wonderful thing about planting native plants is that they are going to be easier to care for because they are already adapted to the environment. However, while this plant is native to our Central Texas environment, we note your question came from France, so in your case, it is a non-native and may require some special provisions for it to flourish. France, like Texas, covers a wide area and includes many divergent climates, soils, elevations and ecologies.

We would hate it if any of the native plants that are so dear to us here in Texas became nuisance, or worse, invasive species in Europe. So we ask that you take particular care to make sure that your Ruellia does not escape from cultivation.

Since we don't know which area of France you may be gardening in, we can only give you the information on where Ruellia davisiorum (Rio Grande wild petunia) occurs naturally and tell you a little about the conditions there. This plant occurs naturally only in extreme South Texas and in adjacent Mexico. The "wild petunia" in the name refers to the fact that the blooms of all ruellias resemble those of Petunia, a genus of South American natives much-hybridized to produce plants of nearly every color but orange. Petunias are not closely related to ruellias.

The environment in Rio Grande Wild Petunia's native territory is generally desert shrub savannah. Soils are dark, calcareous stony clay and clay loams. Altitudes average about 2500 ft. above sea level, and temperatures average from 35 degrees in January to 97 degrees in July. Average rainfall is 17 inches a year.

Just because the native range of Ruellia davisiorum is relatively quite small doesn't mean it's the only place it will grow. There are a number of different types of ruellias, and all are pretty tough and adaptable. For example, Ruellia occidentalis (western wild petunia), is native to larger parts of Texas and therefore not quite such severe conditions. Native habitats of ruellias generally are dry, rocky woods, chapparral hills and flats on the Edwards Plateau and the Rio Grande plains. They are perennials plants. Their light requirements are light shade to shade, but in an area where the sun isn't quite as fierce as it is in Texas, they can probably tolerate more sun. Ruellias' growth habit is as an herb or a subshrub, the soil moisture can be moist or dry, and they are heat and cold tolerant.

We hope this has given you enough information to transform some of your garden into a "little bit of Texas." Best wishes.

 

From the Image Gallery


Rio grande wild petunia
Ruellia davisiorum

Western wild petunia
Ruellia occidentalis

More Non-Natives Questions

Removing a non-native windmill palm from Austin
February 27, 2013 - I have a fairly good size windmill palm (about 15ft high) that is planted too close to the house. I also don't like having to constantly remove its fronds as they block a walkway. Is there a good wa...
view the full question and answer

Locating non-native Bradford pear tree in Austin
June 07, 2008 - Where can I find a Bradford pear tree in Austin, TX?
view the full question and answer

Problems with non-native impatiens in Denton, TX
May 19, 2009 - Dear Mr. Smarty Plants, 4 weeks ago I planted a shady bed (2'x10') with impatiens for the third year in-a-row. Previously, the plants thrived & bloomed till November. Three weeks ago, something ...
view the full question and answer

Replacing yellow bells with hibiscus from San Antonio
July 03, 2012 - Help! Will the roots of the yellow bells keep sprouting if I've removed the shrub? I'm replacing it with a hibiscus shrub. Will it do well in the same spot where the yellow bells were?
view the full question and answer

Plants to replace hydrangeas in a wet area in New York
July 09, 2010 - Dear Smarty, Two years ago I planted 4 Endless Summer Hydrangas in front of the front porch of my summer cottage on Saratoga Lake. The first year they struggled the second they are limp. Can you give...
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