Dietes is a genus of five species, four native to Africa and one to Lord Howe Island off the Australian coast. The name fortnight lily captures its flowering rhythm precisely: the plant produces waves of delicate white and blue flowers at roughly two-week intervals across a long season, with each individual bloom lasting only a day or two. The overall effect, over a clump of long sword-like leaves, is one of continuous freshness rather than dramatic flushes.

Best flowering comes in full sun, though some light afternoon shade is beneficial in hotter climates. It tolerates drought and periods of dryness but rewards regular moisture with denser bloom. Hardy in USDA zones 9 through 11, it can be grown as an annual or dug and stored indoors where winters are cold. Plant rhizomes 12 inches apart and just an inch below the soil surface in fertile, well-drained ground. Avoid cutting back the old flower stems entirely, as new buds form along the same stems for subsequent flushes. Nematodes are the primary pest concern in warm climates.