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 Daphnes are among the most deliciously fragrant of our greenhouse plants. They are generally pretty strong growers, and when fairly established succeed best if planted out along with Camellias and suchlike; but they also make very good pot-plants, provided due care is taken in the way of pinching and training them into form when young; otherwise, if left to themselves, they grow rather bare and straggly. They come into flower naturally in the winter season, which gives them an additional claim to our attention. Though some of the varieties are all but hardy, and all of them thrive well in an ordinary greenhouse temperature, yet while they are in a young state they are the better of being grown in a somewhat higher temperature than that of the greenhouse, say from 55° to 60°. They are not of very rapid growth when young; but by keeping them somewhat warm, they will of course grow into plants of a useful size so much the sooner. They are always much prized on account of their sweet perfume, a small plant when in flower being sufficient to fill a room with its sweet fragrance.
Daphnes can be raised from seed, but as the seed requires about two years to vegetate, this plan is not often adopted; the more general mode being to graft the finer varieties on stocks of the common Spurge-Laurel (Daphne laureola). The soil best suited to their requirements consists of equal parts of good turfy loam and fibry peat, with a good sprinkling of silver sand. The soil should be used in as rough a state as may be consistent with the size of pot used, and the pots should be very carefully drained, as, though the plants require a large supply of water when in full growth, they are very impatient of water lodging about the roots, and will soon fall into bad health should the soil become in any way soured. When the plants have completed their year's growth they should be turned out into a drier atmosphere, to ripen off, and set their flower-buds. After a time they may be set out of doors, in a nice sheltered position facing south; care should be taken, however, that worms do not find their way into the pots - they should therefore be set on an inverted pot, or on a deep bed of fresh ashes.
Should early flowers be wanted, a few plants may be put into a gentle heat in November, and they will come into flower about Christmas. Daphnes are somewhat susceptible to the attacks of red-spider, so that during the growing season the syringe should be freely used among them. The greenhouse varieties are mostly natives of China and Japan; and though the genus consists of a great many varieties, the cream of them is comprised in D. hybrida, D. indica, D. indica rubra, D. odora, and D. odora rubra.