Agapanthus (genus Agapanthaceae) is a fleshy, tender-rooted perennial also called African Lily, Lily of the Nile and African Blue. Its large, rounded clusters of funnel-shaped flowers come in blue, white, indigo or lilac at the end of a thick stem. Agapanthus, which is native to southern Africa, attracts hummingbirds and is a very low-maintenance plant, making it quite popular with gardeners.
Agapanthus grows 2 to 4 feet tall and spreads 12 to 24 inches wide. It grows at a moderate rate in upright clumps. Fleshy rhizomes at the bottom of the plant produce tuberous short roots. The leaves are dark-green, glossy straps in an alternate arrangement. Its flowers rise on sturdy, tubular stems in summer and early fall.
According to the University of Wisconsin Horticulture Department, agapanthus was originally included in the lily family (Liliaceae), was then moved to the amaryllis family (Amaryllidaceae), moved again into the onion family (Alliaceae), went back to Amaryllidaceae and now resides in its own family, the Agapanthaceae, a sister family to the Amaryllidaceae. Early explorers to South Africa first brought agapanthus to Europe in 1679.
Agapanthus grows in USDA hardiness zones 9 through 11. It will not tolerate frost or long winters.
Agapanthus is propagated by dividing its root clumps immediately after flowering.
Seeds are sown in the early spring. To germinate, seeds require temperatures of 70 to 80 degrees F. They'll germinate within three to eight weeks, but it will be three to four years before the plants flower.
Plant agapanthus in well-drained, moderately fertile soil. It prefers full sun in a spot sheltered from wind. In zone 11, agapanthus will do better in partial shade. Agapanthus is not drought-tolerant, but do let the soil dry out between waterings. Too much water leads to yellow leaf tips.
In humid climates, botrytis (a necrotrophic fungus) can devastate the plants, but you can purchase disease-resistant cultivars.
Chewing insects, maggots and borers sometimes will attack agapanthus. Good growing conditions will help the plant resist them.
According to the UW Horticulture Department, agapanthus is considered both a magical and a medicinal plant in Africa, used to treat heart disease, paralysis, coughs, colds and other ailments, and the leaves are used as bandages (the plant does contain chemicals with anti-inflammatory and other properties). However, the plant's sap can cause minor irritation or dermatitis in susceptible individuals, and will cause severe pain in the mouth if ingested.