Ruellia brittoniana - Mexican Petunia

Ruellia brittoniana is not a plant for the faint of heart. The purple flowered Mexican Petunia spreads vigorously. Not so much as can't be contained, but not to be planted and forgotten about either. There is a dwarf variety Ruellia brittoniana Katie 5 feet tall, and a full sized Purple Showers 4-5 feet tall shown below. Ruellia brittoniana can be kept within bounds by planting in a container or in a restricted planter bed, or by using drip irrigation so there is a small oasis in which it can thrive. Ruellia brittoniana roots when the branches touch the ground, spreads 6-12" per year by underground runners and has viable seed. The Mexican Petunia has all of the tools to be a pest, though I have not had too much trouble keeping it in check. Plants are frost damaged in the 20°s F and killed to the ground in the teens. I haven't seen weather yet in our area that might finish off the roots of Ruellia brittoniana.