Zephyranthes candida

Peruvian Swamp Onion Amaryllidaceae

One of the most useful and forgiving members of a genus better known for its tender temperament, Zephyranthes candida is a charming little bulb from South America with an almost absurd ability to produce fresh flowers after rain. Native to Argentina, Uruguay, Paraguay and southern Brazil, it forms neat clumps of narrow, glossy, dark-green leaves, from which arise delicate, upright flowers of pure white, each with a surprisingly elegant greenish throat. The flowers appear from late summer into autumn, often in succession, and are particularly welcome when much of the herbaceous border is beginning to look distinctly tired.

It is probably the hardiest species in the genus, and is sufficiently tough to survive ordinary British winters in a sheltered, well-drained position, particularly once established. Unlike many Zephyranthes, it can be grown successfully outdoors for much of Britain, although a little protection from severe frost and winter wet is sensible in colder districts. It is particularly good planted amongst gravel, at the front of a sunny border or naturalised through short grass, where its flowers can appear almost magically following rain.

The bulbs multiply to form substantial colonies and are remarkably undemanding. Give them full sun and a moderately fertile, well-drained soil, with reasonable moisture during the growing season; summer drought is tolerated once established, but flowering is generally better when the plants are not allowed to become excessively dry. The foliage is semi-evergreen in mild climates and may persist through much of the winter.

The specific epithet candida means pure white, an appropriate reference to the flowers. The common name white rain lily reflects both its colouring and the tendency of the flowers to appear after rainfall. Despite its delicate appearance, this is one of those plants that rewards being treated rather more harshly than its looks suggest.

Height: 15–25 cm
Spread: 20–30 cm
Flowers: August–October
Hardiness: approximately –10 to –12°C once established, with better performance in well-drained soils.