Despite the common name, Mexican heather has nothing to do with the heaths and heathers of the Scottish moors. It is a native of Mexico, Guatemala, and Honduras, a compact evergreen sub-shrub that grows into a neat mound roughly two feet across, with tiny lance-shaped leaves that do, in fairness, bear a passing resemblance to heather foliage. The small lavender flowers appear one by one in the leaf axils all the way up the stems, and the effect when the plant is in full flush is of a fine, shimmering haze of color that lasts from early summer until frost. White and pink cultivars exist for those who want variation.

In warm climates it behaves as a reliable evergreen perennial, but in most North American gardens it is treated as an annual — easy to start from seed indoors eight to ten weeks before the last frost, or from tip cuttings. It asks for good drainage, reasonable sun, and some regular moisture, and it handles summer heat without complaint. Indoors over winter it makes a tidy houseplant in a warm sunny spot, though mealybugs and whiteflies will find it eventually if the air is too dry.