http://www.botany.com/agapanth...
This group consists of tender, evergreen or deciduous plants, which are natives of South Africa and belong to the Lily family, Liliaceae. Most African Lilies are evergreen in mild-winter climates. The fleshy rhizomes of these plants spread over the soil's surface and support a short, more or less tuberous rootstock. Agapanthus, also known as African Lilies and Lilies-of-the-Nile, produce clumps of long, shiny, strap-like leaves, which look attractive even when the plant isn't flowering. Tall stems, reaching 2 to 6 feet in height, are topped with clusters of pretty, white to dark blue flowers from late spring to early autumn. Each flower resembles the flowers of a lily, but are borne in umbels like those belonging to the group, Allium. African Lilies are suitable for growing in the garden, in containers, and as houseplants. They flower better when their roots are rather crowded in a container. The flowers of these plants can be cut for use indoors; they can last up to seven days in a vase. The dried seed heads also look attractive in arrangements.
POTTING: African Lilies are hardy to zones 7 to 11. You can grow them in a colder hardiness zones by planting them deeper than usual and mulching well. They can remain outdoors permanently where temperatures do not fall below 20ยบ F; otherwise, lift them and store them for the winter. Grow African Lilies in well-drained soil consisting of two parts loam, one part leaf mold, and one part well-decayed manure. Plant the roots an inch deep and space the rhizomes 18 to 24 inches apart when grown in a garden. When grown in containers, plant a single rhizome in a 12-inch pot and three in a 20-inch pot. When in active growth, water and fertilize weekly. Site them in full sun or partial shade, unless you live in a hot climate, where they should be set in partial shade.
PROPAGATION: African Lilies should become root-bound before dividing. This usually happens in four or five years. Divide them in the spring by cutting the rhizomes with a clean knife so each section has a few roots. The plants may take a year or so to become established before blooming to their full capabilities. Seeds can also be sown in the spring. However, plants started this way won't bloom until their third year.
VARIETIES
A. campanulatus;
A. africanus;
A. orientalis;
A.umbellatus;
A.mooreanus;
A.praecox;
A. caulescens;
A.inapertus;
A. pendulus.
