Ruellia, Desert Petunia, Florida Bluebells, Mexican Petunia, Mexican Blue Bells 'Katie'

Ruellia simplex

Family: Acanthaceae (ah-kanth-AY-see-ee) (Info)
Genus: Ruellia (roo-EL-ee-uh) (Info)
Species: simplex (SIM-plecks) (Info)
Cultivar: Katie
Additional cultivar information:(aka Katy, Nolan's Dwarf)


Tropicals and Tender Perennials

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Sun Exposure:

Full Sun



Foliage Color:

Dark Green


under 6 in. (15 cm)


9-12 in. (22-30 cm)


USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Where to Grow:

Grow outdoors year-round in hardiness zone

Suitable for growing in containers



Bloom Color:



Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall

Blooms repeatedly

Other details:

May be a noxious weed or invasive

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

By dividing the rootball

From herbaceous stem cuttings

Self-sows freely; deadhead if you do not want volunteer seedlings next season

Seed Collecting:

Bag seedheads to capture ripening seed

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


This plant is said to grow outdoors in the following regions:

Dothan, Alabama

Loxley, Alabama

Chandler, Arizona

Goodyear, Arizona

Marana, Arizona

Phoenix, Arizona

Scottsdale, Arizona

Yorba Linda, California

Brooksville, Florida

Delray Beach, Florida

Fort Lauderdale, Florida

Hollywood, Florida

Keystone Heights, Florida

Lakeland, Florida

Ormond Beach, Florida

Alpharetta, Georgia

Decatur, Georgia

Baton Rouge, Louisiana(2 reports)

New Iberia, Louisiana

Shreveport, Louisiana

West Monroe, Louisiana

Hulbert, Oklahoma

Stilwell, Oklahoma

Conway, South Carolina

Summerville, South Carolina

Smyrna, Tennessee

Alvin, Texas

Austin, Texas

Baird, Texas

Bellville, Texas

Brownsville, Texas

Converse, Texas

Denton, Texas

Elgin, Texas

Fort Worth, Texas

Garland, Texas

Houston, Texas

Katy, Texas

Mc Kinney, Texas

Missouri City, Texas

New Caney, Texas

Portland, Texas

Richmond, Texas

Rowlett, Texas(2 reports)

San Antonio, Texas(2 reports)

Santa Fe, Texas

Kalama, Washington

show all

Gardeners' Notes:


On Sep 4, 2018, legalsmith from Baton Rouge, LA wrote:

I love this plant! In 2009, I planted lavender, pink and white varieties in my back yard where I have big dogs. They bloom from early summer until it freezes, if it freezes. Evergreen in mild winters, it will freeze to the ground and return in spring when we have a hard winter.
Not only is it consistently in bloom, it is a very rugged plant that withstands my big dogs and even bigger people walking on it. It has spread well in the years since I planted it, and I have encouraged this, trying to get it to the point of ground cover. I have not found it to be invasive, like I understand the larger ruellias are, though I understand it may be so in Florida and precautions should always be taken when this is an issue.
This is such a cheerful plant, always blooming and often crow... read more


On Nov 16, 2015, siege2055 from Stilwell, OK (Zone 7a) wrote:

This one self sows a lot, I have them coming up all over my porch in the cracks between the boards, and in my other potted tropicals as the seedpods are explosive. I have also collected and tested the seed and they germinate very easily, I have not grown any of the seedlings large enough yet to determine if they are going to be dwarf or revert back to the taller form, but in warmer places Katie could be invasive if it reverts, judging by all the seedlings I have all over the place. Here I doubt the smaller seedlings will make it through the winter, but we shall see. If the seedlings grow true, then yay! I will have hundreds of them. I am going to start a tray of 72 seedlings this spring to see what happens, I will update this when I find out as I am sure others would like to know, but afte... read more


On Apr 30, 2011, txsage from Katy, TX wrote:

This one grows like a weed - healthy and blooming most of the time, Houston heat and cold tolerant. Freeze kills foliage, but not roots, comes back every year, often in new places.


On Nov 18, 2007, Riverland from Northeast, LA (Zone 8a) wrote:

I absolutely love this plant stays contained in clumps for me. This is not the mexican Petunia that is considered invasive , It does not develop seed and throw them all around like it's tall cousin.
Vossner I'll take your excess. Trades well cause it travels well. Vossner sent me white and it pouted a day or two and recovered to its beauty.


On May 26, 2007, vossner from East Texas,
United States (Zone 8a) wrote:

This plant annoys me sometimes because it does spread; however, they are very easy to remove at any stage of growth.

Excellent for front of border, fillling bare spots, container gardening


On May 24, 2007, WUVIE from Hulbert, OK (Zone 7a) wrote:

Recently I acquired "Katie Bluebells" from an aquatic
plant source. It was thriving in a shallow pond, so I found
it odd that information above mentions not to overwater it.

The plants were all blooming and beautiful, sitting in
tight little pots of kitty litter in a short few inches of water.

The plants I purchased, brought home and stuck into the
pond are doing quite well.

For those concerned with it's 'invasive' qualities, it can always
be planted in pots, or in pot-in-pot designs in the ground. Very
easy to solve.


On Jun 13, 2006, MizCharlie from Winter Garden, FL wrote:

I tried to add a note regarding the danger of this plant. Here's what the Florida Dept of Ag says about it:

"Mexican petunia has been designated by the Florida Exotic Pest Plant Council as a Category I invasive plant. That means it has the ability to displace native plant species so as to alter native plant communities. While it is not illegal to plant it, unintended consequences can last for ever."


On Jul 16, 2004, cheryldawn from Lakeland, FL wrote:

I live in lakeland Florida. I bought a pink Mexican petunia four years ago . It's now almost 2 1/2 foot high. I have 13 plants now from cuttings and some from little baby plants that came from it. It must be the less invasive variety as mine has little cane like stems and are compact and very
attractive and tropical looking where as my sisters are on long grass like stems and they spread all over.
I live in Florida where it gets hot and humid and lots of plants get cooked in the summer. This plant just blooms spring till summer and nothing seems to bother it. I've never had a plant bring me so much happiness.
I bought two purples ones a few weeks ago at Home depot, but don't know if they're dwarfs or going to get 2 1/2 foot tall like my pink ones or not. It didn't ... read more


On Mar 11, 2004, sweezel from McKinney, TX (Zone 8a) wrote:

Much more interesting and much less invasive than the other cultivars. I planted my transplant in May and it had expanded to at least twice it's original size by frost so it is good for filling in spots quickly. Also, it is very easily divided if it spreads out because the stalks pull up separately. Also comes in white or pink blooming varieties.


On Sep 26, 2003, CDauphinet from New Iberia, LA (Zone 8b) wrote:

It's easy to divide and share this plant: pull the extra stems off, making sure there's a bit of root attached. Just stick it in the ground - very easy to grow. I also have the pink and grows just as well!


On Sep 25, 2003, htop from San Antonio, TX (Zone 8b) wrote:

"Katie" is sometimes called Nolan's dwarf. Shortly after Lynn R. Lowrey, a well known Houston horticulturalist and collector (considered to be the founder of the native plant movement in Texas) sold his nursery in Conroe, Texas, to his friend Katie Fergerson, two employees, Herbert Durand and Nolan Guillot, discovered a short growing natural hybrid Ruellia. After it was brought to Lowreys attention, he began testing, cultivating, sharing and promoting it after naming it after his friend. Both Katie Fergerson and Lynn Lowery are now deceased, but their contributions to horticultural endeavors live on.

It is a plant which forms clumps 6-10" tall and 12" wide, it is a super border and/or ground cover plant which begins blooming profusely in mid-summer to late summer and conti... read more