Purrsian Blue is a catmint bred to behave: a dense, tidy mound about 18 inches tall that doesn't flop open at the center the way older catmints do. Aromatic gray-green foliage disappears under periwinkle-blue flower spikes from early summer into fall, and bees hum over it all day.

Give it full sun and well-drained soil; once established it handles drought easily. Deer and rabbits avoid the scented foliage. Shear it back by half after the first big flush and it regrows quickly and blooms again.