Mexican petunia

Ruellia brittoniana


The Mexican petunia is a low mounding perennial with long dark evergreen leaves and purple-blue flowers that cover the plant from spring into summer. This species grows 12-15 in. high and to 24 in. wide with a compact habit. One popular cultivar, R. b. ‘Katie’, is smaller with a mature size 12-15 in. in height and 15-18 in. wide. These plants are valued for their attractive foliage and large purple petunia-like flowers.

This southwestern native is highly ornamental and useful for small spaces in Inland Empire gardens where it grows best with regular water and protections from hot sun exposures. It is cold tolerant, surviving temperatures below 20°F, and maintains good foliage character throughout the year.

Plant Type: Perennial
Foliage Character: Evergreen
Habit: Mounding, Compact
Growth Rate: Moderate
Foliage Color: Dark green
Flower Color: Purple
Flower Season: Summer, Spring
Soil Adaptations: Well-draining soil, Sand, Clay
Exposure Adaptations: Morning sun, Heat, Frost, Partial sun
Function: Rock gardens, Hummingbird plant, Flowering accent plant, Container plant, Borders, Small spaces
Height: 12 in. – 15 in.
Width: 24 in.