This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
Among the most delicate and fragrant early flowers these Gardenias may be classed; for they are now forced forward in abundance to meet the demands of our markets and gardens, and cultivated to a great extent for cut flowers. Both the above species strike freely from cuttings placed in silver sand, under bell-glasses, if favored with a gentle bottom heat; their after-management is equally simple, if, after sufficient root is made, they are potted off and transferred to a common hotbed, plunged to the rim, and kept growing till they actually flower; the principal thing to bear in mind in their cultivation is, that they delight in moist peat, and in nothing so much as a common hotbed. A few pots in a cucumber frame will do well, insomuch that they who grow for supplying Covent Garden find it the most profitable as well as the most effective; the heat afforded is just what the plants require, keeps off red spider, thrip, mealy bug, and other entomological pests, to which they are so liable in the stove. When the plants are large, they should be transferred to a moist stove or orchid-house, or they are in danger of receiving a check they do not get over without considerable care and trouble, and frequently not at all.
If cuttings were taken off at the time when last year's shoots had made all their growth, they will root and flower before they are more than three inches highland even in thumb-pots, although for specimens this would not be allowable. Few plants surpass them in delightful fragrance, and they yield an abundance of lovely blossoms at a time when they are very serviceable. - London Florist.