Host an Event Volunteer Join Tickets

Support the plant database you love!

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

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
4 ratings

Saturday - October 03, 2015

From: Wentzville, MO
Region: Midwest
Topic: Non-Natives, Herbs/Forbs
Title: Overwintering Ruellia brittoniana in Missouri
Answered by: Anne Van Nest

QUESTION:

I live in Missouri and have five beautiful Mexican Petunia or Ruellia brittoniana planted and established in my landscaping. With winter fast approaching, I would love advise on how to winterize the plant's so they can survive our Midwestern winter!

ANSWER:

Overwintering Ruellia indoors is possible and best achieved by taking cuttings in late summer and growing the rooted cuttings through the winter. Moving a container plant inside in the fall can also be successful but runs the risk of bringing in pests with the plant. Transplanting from the garden is less successful because of the shock to the plant.

The Missouri Botanical Garden have a good information page on Mexican Petunia, a non-native plant. Here is part of what they say:

Winter hardy to USDA Zone 8 (marginally hardy in Zone 7 with protection and mulch) where it is best grown in medium to wet soils in full sun to part shade. Best flowering is in full sun. This plant thrives in moist, fertile, humusy but well-drained soils. It is a versatile plant that tolerates an extremely wide range of growing conditions. It thrives as a marginal water plant and in boggy soils. It also does well in average garden soils with even moisture. Established plants have respectable drought tolerance. Plants also tolerate high heat and humidity. Cut back stems after flowering to encourage new flowers. Plants will spread by rhizomes and self-seeding in the garden, and have escaped gardens and aggressively naturalized in parts of the southeastern U. S. Notwithstanding its value as an excellent flowering plant, this species is currently listed as a Category One invasive species by the Florida Exotic Pest Plant Council (FEPPC) because it has been found to invade natural areas and displace native flora in the State of Florida. Plants are most invasive in moist areas. Invasiveness is clearly not a problem in St. Louis, however, where these plants are grown as annuals, with stem cuttings overwintered indoors if desired. Easy to propagate by cuttings, division and seed.

Ruellia simplex, commonly called Mexican petunia or Texas petunia, is a vigorous, shrubby, woody-based, rhizomatous perennial that is grown as an annual north of USDA Zone 8. It is native to Mexico, but has escaped gardens and naturalized somewhat aggressively in parts of the southeastern U. S. from South Carolina to Texas plus Hawaii, Puerto Rico and the U. S. Virgin Islands. It typically grows to 3-4’ tall in the wild, but to 2-3’ tall in gardens. Plants branch from the ground into several woody-based stems clothed with elongated, linear, willow-like, dark green leaves (to 6-12” long and ¾” wide) that are often tinged with purple. Tubular, trumpet-shaped, 5-lobed, petunia-like, lavender to violet flowers (to 1.75” long) bloom from the upper leaf axils in loose purple-stemmed clusters (long-stalked cymes). Each flower blooms for only one day. Best flowering occurs in the deep South near the temperatures of its Mexican origin where flowers may appear from May to November, but sometimes year round. Flowering is very respectable but less frequent when plants are grown as annuals in northern gardens where they typically bloom from May to September. Flowers are followed by bean-like pods (to 1” long) which explosively dehisce ripened seed in all directions.

Considerable confusion has existed over the years as to the correct specific epithet for this plant. It is been given a number of different names, including R. brittoniana, R. coerulea, R. malacosperma and R. tweediana. At this time, Ruellia simplex is the preferred specific epithet because it has been determined that this was the name first given to this plant in 1870 when it was described in Cuba, and accordingly that name has priority.

 

More Non-Natives Questions

Managing non-native invasive creeping yellow cress in Rio Medina TX
January 10, 2012 - Due to my lawn mower dying and waiting for the shop to fix it my yard got a bit overgrown. I was walking around the yard looking at the blooming wildflowers and have discovered that one of them is Ror...
view the full question and answer

Blocking stolons of St. Augustine grass
July 25, 2008 - I have St. Augustine in my yard, and I am sick of edging the stolons that grow onto the sidewalk and driveway. Is there any way to stop the stolons or block them so that I can just mow and throw away ...
view the full question and answer

Yellow bands around edges of leaves in Whitney TX
July 20, 2009 - How can you tell whether esperanzas are getting too much water or not enough - ours have a small yellow band around the edges of the leaves - crape myrtles - same question
view the full question and answer

Plants looking similar to Camellia sinensis in Venezuela
June 30, 2008 - Is there another plant that looks similar to the tea plant? I need to do a photoshoot of a tea plantation, but canīt really get to one, so I was wondering if there were other plants that at least look...
view the full question and answer

Thinning and culling wildflower seed mix plants
May 11, 2015 - Wildflower garden in central Oklahoma I sowed a (mostly) native wildflower mixture in early November here in my Zone 7A Edmond, OK garden. To my surprise, many of the seeds (I'm guessing annuals)...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.