This section is from the book "The Gardener V3", 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 Eriostemons are all natives of New Holland, and are among the finest and best of our hard-wooded greenhouse plants. They are mostly compact-growing evergreen shrubs, and are very free-flowering. The flower-sprays are admirably adapted for arranging in vases. When of the proper size, they make capital dinner-table plants, and a good well-grown specimen is a very telling object on the exhibition-table. They are purely greenhouse plants, and if a proper selection of varieties be made, may be had in flower from February till October : such kinds as E. neriifolius and densifolius, coming into bloom in February; E. buxifolius and E. liniaerifolius bloom from March till June; E. myoporoides from May till September, and E. cuspidatus from May till October. These are among the best of the genus. They should be grown in good fibry peat, with a little turfy loam and a good proportion of sharp sand incorporated with it. They will not stand much artificial heat, and they should be kept moderately dry during winter, as a damp atmosphere or over-watering is very injurious to them.
They are increased by cuttings of the young shoots, which should be slipped off with a heel, about the end of March or during April. The pots to receive the cuttings should be well drained, and half filled with soil from the potting-bench, and then filled up with pure silver sand. After giving a watering through a fine-rosed pot to settle the sand, proceed to put in the cuttings, water again, and cover with a bell-glass, then plunge the pot in a mild hotbed until the cuttings strike root. As soon as they have fairly rooted, they must then be potted off singly into small pots, and replunged in the hotbed until they root afresh into the new soil, when they may be taken out of the plunging material, and either set on the surface or on a shelf near the glass. Care must be taken that they do not suffer from want of water in this young state. They must be shifted on into larger pots as they require it; and in potting, the soil should be rammed pretty firmly into the pots and round about the ball, so that the water may not escape too readily through the fresh soil, and the ball become too dry in consequence.
They will require to be pinched occasionally when young, to get them into shape, and to make a good foundation at first, after which they will not give much trouble in the way of training, save a partial cutting back of rampant shoots now and again. They stand the knife well, so that should they at any time become too big, there need be no hesitation in cutting them pretty hard back, as they will break away again freely. When the early-flowering varieties have ceased flowering, and as soon as the weather permits, they may be set out of doors, in a sheltered sunny position, to mature their growth, as on this depends very much their flowering freely next season. A temperature during winter of from 45° to 50° will suit them well. They are not much troubled with insects, but are occasionally attacked by scale, and a kind of smut which blackens the stems and leaves, rendering them unsightly. This must be overcome with brushing and syringing with warm soapy water, or any of the hundred and one nostrums for killing scale, etc. As simple a remedy as any for brown-scale, is to dip the plant in water heated to 140° Fahr.: this will effectually kill all the scale, without doing harm to the plant.
J. G., W.