Ruellia caroliniensis

Ruellia caroliniensis, the Carolina wild petunia, is a modest, long-blooming native that carries far more ecological weight than the quiet flowers suggest. From early summer into fall, a steady succession of lavender to violet-purple trumpets, each an inch or two across and lasting only a single day, opens along upright stems a foot or two high, replaced faithfully the next morning so that the plant is seldom out of bloom for months on end.

The wild petunia is no true petunia at all, but a member of the acanthus family, and takes the genus name Ruellia in honor of Jean Ruel, the sixteenth-century French herbalist and physician. The species belongs to the southeastern and eastern United States, ranging from New Jersey and Ohio south to Florida and Texas, at home in open woods, sandy pinelands, roadsides, and dry clearings, where the plant seeds about gently and never becomes a nuisance.

For all the plainness of the flowers, the Carolina wild petunia is a pollinator engine, feeding bees, butterflies, wasps, and even hummingbirds through a long season, and serving as a larval host plant for the common buckeye and white peacock butterflies, whose caterpillars feed on the foliage. Growing this native, in other words, does real work: not just nectar, but the leaves that raise the next generation of butterflies. Few small perennials give so much back to the garden's wildlife.

In the garden, the wild petunia belongs at the front of a border, in a native or pollinator planting, a wildlife garden, or an open, sunny bed, where the low, bushy form and steady bloom fill in among grasses and other natives. Give full sun to part shade and ordinary well-drained soil, and the plant asks little more, tolerating drought once established and blooming hardest in sun. Deadhead or shear to keep the mound tidy, let a few seedlings stand to carry the planting forward, and enjoy a quiet, indestructible native that earns a place through sheer usefulness.