The Confusing Ruellias

The Confusing Ruellias

 Invasive Ruellia

Usually when Floridians discuss Ruellia, they refer to the invasive Mexican petunia (Ruellia tweediana syn. R. brittoniana). Although quite beautiful, this exotic invasive plant is not recommended for landscape use by the Institute of Food and Agricultural Sciences at the University of Florida. Understandably, it is a Category I species listed on the Florida Exotic Pest Plant Council’s list of exotic plants that are invasive in North Florida. Environmentally sensitive gardeners do not include this plant in their landscapes because they know that it escapes into natural areas and displaces native plant species.

Elegant Ruellia

However, don’t make the mistake of avoiding a plant just because “ruellia” is part of its name. Other species exist which are wonderful garden plants. A pretty, well-behaved variety from Brazil has earned its keep in gardens across the South, and it has not misbehaved according to any reports I have heard. On the contrary, it is highly recommended. One gardener from Texas says that it is “an outstanding tough continual bloomer which grows well in our heat and humidity.” This gardener rates the plant a 10+++ on a 10 point scale.

Ruellia elegans, or elegant ruellia as it is often called, has bright red trumpet shaped flowers that are magnets to hummingbirds and butterflies. Each flower is held above the foliage on 6- to 8-inch wandlike stems. The upper two petals reflex upward and backward and touch each other at the top, while the remaining three petals open wide to reveal the one- to two-inch wide blossom.

The blossoms appear from May until frost. Plants will take light frosts, but die back at about 28°F. In our area they return reliably each year. Plants grow a modest 12 to 14 inches tall and very slowly and gradually form a clump about 12 to 18 inches wide. Foliage is medium green, semi-fuzzy, and soft to the touch.

Culture

Blooming is most prolific in full sun, but elegant ruellia also grows well in partial sun. Plant in soil that has been amended with organic matter, and fertilize with slow-release, balanced fertilizer in spring as growth begins and perhaps once again in mid-summer. Elegant ruellia is moderately drought tolerant, so a deep watering in the absence of rain may be beneficial. Seemingly immune to pests and diseases, it is a carefree addition to the perennial border. Plants are hardy in USDA Zones 7B-10.

Use elegant ruellia at the front or edges of borders so that its vivid flowers can be seen. I have grown this perennial for several years, and in that time it has been a favorite not only because of its beauty, but also because of its reliability and toughness. This elegant flower truly lives up to its name.

At a Glance

Scientific name: Ruellia elegans

Say: roo-EL-ee-uh ELL-eh-ganz

Common names: Elegant ruellia, Thai ruellia, Brazilian petunia

Plant type: Hardy perennial

Hardiness: USDA Zones 7B-10

Exposure: Full to partial sun

Size: 12-14 inches tall/12-18 inches wide

Propagation: Division of clumps

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