Salvia coccinea - Snow Nymph
This frilly salvia looks delicate, but it's as durable as anything in your garden. Thick clusters of snow white blooms grow on 2' foot stems that can topple from the sheer weight of the blossoms. Pinch it back. It will only bloom more.
Native to South America, Salvia coccinea is at home in zones 7-10. It does best in dappled sun or partial shade, is drought-tolerant, and is ideal for containers. It makes a fine cut flower and looks at home in a cottage garden, but is sturdy enough to thrive next to cactus. Plants only live two or three years unless they're cut back hard, but they're easy to start from seeds or cuttings.
Hummingbirds love this plant!