Riptide carries periwinkle-blue flowers with white centers on a plant that stays dense and mounded instead of opening up in the middle. This Proven Winners® selection, Stokesia laevis Totally Stoked Riptide, grows 24 to 26 inches tall and spreads 32 to 36 inches in full sun, hardy from Zone 5 through Zone 9.
Bloom comes in midsummer, which is unusual for something sold as an aster, and the flowers are large and fringed rather than daisy-shaped. Deadheading extends the display. They cut well and hold in a vase.
The foliage is strap-shaped and evergreen through winter in the milder parts of the range, forming a low rosette that stays tidy once the flowers finish.
Stokes' aster is a southeastern native, and heat tolerance is where it earns its place: it keeps flowering through humid summers that flatten other perennials. Well-drained soil matters more than anything else, since winter wet is the usual cause of failure. It also handles drought and moderate road salt once established, and deer leave it alone.