Azalea

Where it grows

Botanists no longer separate azaleas from the genus Rhododendron, but gardeners still group them as deciduous and evergreen types. The Kurume azaleas of southern Japan are a backbone of suburban shrub planting from Tokyo to Atlanta; the deciduous Knap Hill and Exbury hybrids developed in early-twentieth-century England remain reference scented forms.

How to recognise it

Azaleas are smaller-flowered than most rhododendrons, with funnel-shaped blooms two to five centimetres across crowded in clusters at the branch tips and five stamens (rather than the rhododendron’s ten). The leaves are smaller, often softly hairy, and either deciduous or evergreen depending on the group.

Garden & cultural uses

Like all ericaceous shrubs, azaleas require acidic, free-draining soil and dislike lime; chlorotic yellowing leaves often signal soil pH problems. Bowls of azaleas in full bloom are a fixture of Lunar New Year markets in Hong Kong and Taiwan. Mass plantings light up cemeteries and parks across the American South each April.

In safety

All parts contain grayanotoxins, and honey made from Pontic azalea (R. ponteum) nectar — the so-called “mad honey” of the Black Sea coast — is mildly hallucinogenic and historically used as a weapon to disable invading armies.