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 above genus contains some of the most beautiful of our flowering greenhouse plants. They are generally easily grown, and are very free bloomers, as well as being very sweet-scented. They are admirable for cutting from, and also for house-decoration, and are among the best of exhibition plants - indeed they formerly used to be considered indispensable on the exhibition-table, but, like many other kindred subjects, have for some years been all but unrepresented at our exhibitions. We hope, however, to see them again reinstated in their wonted place. They are all natives of New Holland, and therefore do not require a high temperature to grow them - a winter temperature of between 40° and 50° being amply sufficient for them. They are propagated from seed and by cuttings; the latter being the mode more generally adopted.
Cuttings of the young shoots should be taken off in spring, and put in under a bell-glass, in a properly prepared pot, such as has been often described before, and the pot plunged in a mild hotbed. They must be potted off singly into small pots as soon as they are sufficiently rooted, and the pots replunged in the bed until they get a fresh start. The soil should consist of good fibry peat, two-thirds, and one-third of turfy loam, with a sufficient quantity of silver sand to keep it open. Of course for the small plants the soil must be sifted, but for all sueceeding shifts the soil should be in a rougher state, the pots carefully drained, and the soil rammed rather firmly in the pots. They must be watered carefully, particularly after potting, and at this time they should be kept for a while pretty close and warm. A 3-inch pot will be quite large enough for them the first season, and in the following March or April they may be shifted into larger pots, and the points pinched out, which operation should be repeated a few times, so as to secure a good foundation for the future specimen.
It requires a number of years to get up a large specimen, but plants in 5- or 6-inch pots make most useful subjects for general decorative work. The time of their flowering is from May to July, according to the variety. The genus comprises several varieties, and all of them are worth growing; but a selection of half-a-dozen varieties will generally be found sufficient. P. decussata, P. elegans, P. Hendersonii, P. spectabilis, P. diosmaefolia, and P. Neippergeana will be found to give general satisfaction.