Commonly called Lily of the Nile, Agapanthus is a perennial plant that originally hails from South Africa. The Agapanthus will shoot out a tall stem that can reach 6 feet in height, topped by a flower that, when opened, is usually a brilliant blue or lavender. Agapanthus flowers in the summer and is hardy outdoors only in warm climates (USDA zones 9 to 11). In areas with colder winters, potted bulbs can be brought indoors over the winter and moved outdoors again in summer.
Plant your Agapanthus in an area that receives full sun if you live in a mild climate. If your summers tend to be hot, give the plant partial shade.
Tolerant of just about any soil, the Agapanthus does best in a well-drained plot containing soil amended with well-rotted manure and organic mulch material.
Water the Agapanthus weekly in the summer but in the winter allow it to dry out a bit more between waterings.
Fertilize the Agapanthus in early spring, and then again in mid-summer. Make sure that the soil is wet prior to applying the fertilizer.
Check the Agapanthus frequently for signs of botrytis, a disease caused by a fungus. Symptoms of botrytis are brown spots and gray or brown dust-like spores on the leaves. Treatment involves removing any diseased parts of the plant, sometimes the entire plant will need to be destroyed. Fungicides are also effective, depending upon the type of Agapanthus.