Buddleia davidii (Butterfly bush, Summer lilac)

Butterfly bushes are carefree deciduous shrubs that are reliably fragrant and easy to grow. Butterflies swarm to their blooms all summer long. 'Lochinch' has extremely fragrant lilac-blue flowers with orange eyes. It is a cross between B. davidii and B. fallowiana. Its arching, mounded habit typically reaches 3 to 5 feet in one season, but can grow much taller in the deep South. The 8-  to 12-inch-long flower spikes begin in late summer and bloom until frost, starting a little later than the B. davidii cultivars.

Butterfly bushes are carefree deciduous shrubs that are reliably fragrant and easy to grow. Butterflies swarm to their blooms all summer long. 'Black Knight' has deep purple-blue, almost black, flowers in elongated clusters on arching branches to 10 feet tall if not cut back, and half that size if cut back. The blooms come from early summer to first frost. The foliage is willow-like and grayish green.

Giant-flowered purple sage has been winning over gardeners the past few years for its remarkable summer blooms and tough-as-nails demeanor. Native to the dry foothills and mountains of southern California, this sage is considered a woody shrub. It features showy, aromatic silver foliage and bicolored flower spikes with lavender-purple calyces and long, hummingbird-pollinated blue flowers. It grows from 24 to 36 inches high.

'Diana' has deep green foliage and large, pure white flowers that bloom from mid- to late summer. Unlike some other roses of Sharon, its flowers remain open at night. It requires little maintenance and, once established, will tolerate extreme heat, drought, and poor soil.