Plant of the Month

Ruellia: A Plant of Many Virtues

By Marnie Barnes Sadri

Imagine a garden blessed with dazzling purple, trumpet-shaped blooms that return anew each morning for nearly five months of the year. Picture a plant that not only survives but thrives in Texas heat and humidity, and even tolerates drought with ease. Envision a garden companion that settles in gently—never crowding its neighbors, even after many years. Now, add the delight of knowing this same plant provides food for butterflies such as the Common Buckeye and the Wood Nymph, while also serving as a nectar source for pollinators and the occasional hummingbird. Best of all, it flourishes in sun, shade, or anything in between, returning faithfully each spring like an old friend.

Meet my favorite: Ruellia drummondiana.

Several Ruellia species are native to Texas and do well in DFW gardens, including Ruellia nudiflora (Common Wild Petunia), Ruellia occidentalis (Western Wild Petunia), Ruellia humilis (Prairie Petunia), and Ruellia caroliniensis (Carolina Petunia). But only one species is endemic to Texas—occurring nowhere else in the world: Ruellia drummondiana, or Common Wild Petunia. It was named for Scottish naturalist Thomas Drummond, who collected and cataloged plants across Texas in the early 1800s, particularly around the Edwards Plateau and Brazos River region.

Though it is concentrated in the Edwards Plateau, Drummond’s Ruellia can also be found in the Cross Timbers, Blackland Prairie, and even parts of the DFW area. I first discovered it nearly 20 years ago on the edge of my Denton garden, then a heavily wooded, undeveloped lot. At first I mistook the ovate-leaved newcomer for a weed and pulled it up—only to have it reappear. A year or two later, when the plant revealed its striking blooms, I began to understand its charm.

Unlike R. nudiflora, whose flowers cluster at the tops of its stems, Drummond’s flowers bloom gracefully along the main stem where the leaves meet, creating a lovely layered effect. Around the same time, I noticed Buckeye butterflies lingering near it—only later learning that Ruellia drummondiana is in fact the larval host for the species.

Through the seasons, I observed how adaptable it was: thriving equally well in full sun alongside prickly pear, or in the deep shade beneath redbuds and post oaks. Unlike its more aggressive cousins, it produces only a few seeds per pod, preventing it from spreading invasively. This makes it a gentle, well-mannered addition to a native garden.

That restraint is worth noting, because not all Ruellias are so considerate. Take Mexican Petunia (Ruellia simplex), for instance. With its tall, dark foliage and equally beautiful blooms, it may tempt gardeners—until it reveals its invasive nature, spreading aggressively by underground roots and explosive seeds, often overwhelming everything in its path.

By contrast, Texas’s own Ruellia drummondiana is a true garden treasure: hardy, graceful, pollinator-friendly, and uniquely ours. For Texans—native or transplanted—it’s a plant well worth welcoming into the garden.

Birding with Jack: The Weekly Bird Census

Wayne Meyer, Nancy Riggs, Jack Chiles, and Mike Petrick

Each Tuesday a team of experienced birders, including Master Naturalist Jack Chiles, traverse 35 miles of refuge roads and hiking trails, documenting every bird they encounter. This Bird Census is reported to The Cornell Lab of Ornithology for use in research, and each week we will bring you a link to their actual bird count, and a summary of their adventures.

See the rest of Jack's notes and the latest Bird Census Results       

Junior Ranger Program: Advanced and Intermediate

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