Ruellia brittoniana "Katie' or 'Nolan's Dwarf"

The 'Katie' Ruellia is the well-mannered dwarf of the Mexican petunia, a low, spreading mound barely a foot high that blooms without pause from summer until frost. Above narrow, strap-like, dark green leaves open a steady succession of bluish-purple, trumpet-shaped flowers, each an inch and a half across and lasting but a single day, replaced the next morning by a fresh crop. In Charleston, South Carolina, gardeners know the tribe by the charming old name Breakfast Flower, for the way the blooms greet the day and are gone by evening.

The dwarf carries a good Texas story. Shortly after Lynn R. Lowrey, the celebrated Houston horticulturist often called the father of the Texas native-plant movement, sold his Conroe nursery to his friend Katie Fergerson, two of the staff, Herbert Durand and Nolan Guillot, spotted a short, naturally occurring hybrid Ruellia among the stock. Lowrey took the plant up, tested and propagated and shared it, and named the selection 'Katie' for his friend, though the plant travels just as often under the name 'Nolan's Dwarf'. Both Katie Fergerson and Lynn Lowrey are gone now, but their work lives on in every low mound of purple that opens at breakfast.

Where the tall Mexican petunia, Ruellia simplex, has earned a hard reputation as an aggressive seeder in warm climates, 'Katie' is a far better citizen: the dwarf sets no seed, spreading only slowly by rhizome, so the plant stays put where the towering parent would run. Use 'Katie' as a tough, long-blooming edging, a front-of-border ribbon, a groundcover for a hot bank, or a filler in a large container, where the low purple mound reads against gravel, stone, and paving. The flowers draw butterflies and bees all season.

Few plants are so forgiving of heat, drought, and poor ground: 'Katie' takes full sun to part shade and almost any soil, from dry to seasonally wet, blooming hardest in sun and asking for little once established. In the warmest zones the mound stays evergreen; from about zone 8 the top dies back in winter and returns from the rhizomes in spring, so mulch the crown where freezes are sharp. A small, indestructible plant with a big season and a good story behind the name.