This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
The Agapanthus, or African Lily, is a plant that one very seldom sees in any collection of greenhouse plants, and yet in its own way it is a very useful and decorative plant for entrance-halls, lobbies, or conservatory, and associates well with palms or other foliage-plants, the light blue of its flowers being a very attractive colour. It only requires to be protected from frost during winter, and will grow and flower freely in any sheltered position out of doors during summer and autumn, but generally speaking, is all the better of being under glass. It throws up a strong flower-stem, about 2 feet high or so, with umbels of flowers at the top, which continue to expand one after another for a considerable time. The Agapanthus are strong-rooting plants, and therefore they require a moderately rich soil, of which good turfy loam should form the staple, enriched with some old cow-manure, and sufficient sharp sand to keep it open. There is also a white variety of the Agapanthus, named A. umbellatus albiflora, which is deciduous, and of course should be dried off and allowed to rest during winter.
J. G., W.