May White Azalea

Size, growth and what to expect

No source rates its growth, so our growth estimator treats it as slow, about a foot a year, like our other wild azaleas. Wild plants grow into shrubs or small trees up to 15 or 16 feet tall.

Clusters of five to ten white funnels, about 2 inches across, open in May and June after the leaves have expanded. Each has a yellow to orange blotch and pink stamens, and the scent is strong. Eastern tiger and pipevine swallowtails and bumblebees visit the flowers.

It grows in 13 counties of the South Carolina piedmont and coastal plain, most often along the Broad and Congaree rivers. Its home is mature hardwood forest on north-facing slopes above streams, often near limestone. A census in the Sumter National Forest from 2018 to 2021 counted 2,035 plants in 38 stands.

How to grow May White Azalea

May white azalea does best in part to full shade under tall hardwoods, as on a north or east slope above a stream. It wants a moist sandy loam, slightly acid to nearly neutral. It does not survive on the driest sites. Set plants 6 feet apart. At its size it can go within 15 feet of overhead wires.

Saplings ship potted. Plant dormant plants in early spring or fall, in a hole three times as wide as the root ball and no deeper. Set the top of the ball a touch above grade, and put the native soil back in. Mulch with leaves, kept off the stems. The seed is dust-fine and needs light but no chilling. Sow it in winter on the surface of damp milled sphagnum, uncovered, under a clear cover at room temperature. Seedlings come up in one to three weeks.

Water weekly through the first two summers, and keep the soil moist. Deer stunt young plants in the wild, so cage it where deer are common. Prune, if at all, right after bloom.

Each flower carries both male and female parts, and swallowtail butterflies and bumblebees visit the flowers. Sources disagree on whether a native azalea sets seed with its own pollen, so plant two seedlings from different parents for seed. Wild plants fruit only now and then, perhaps for want of pollinators. Like other rhododendrons, it is poisonous in every part if eaten.