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.
In one or other of its several varieties this is the best known, and the best worth growing, of this pretty group of greenhouse plants. There are several other species which have been introduced from time to time, but none of them have risen in popularity, as decorative plants, so much as the one named above. All the species were better known formerly under the names Helichrysum or Helipterum - two genera of popular annuals with everlasting flowers. The flowers of Aphelexis, too, are everlasting, but resemble more closely in form and colour Rhodanthe than Helichrysum. Aphelexis humilis is a pretty plant and interesting, whether in flower or not, somewhat straggling in habit, but capable, with a little care and skill, of being manipulated into specimens of perfect symmetry, and when well bloomed it is an ornament of a choice and distinct kind, lasting for many weeks with little diminution of its freshness. There are several varieties differing from the ordinary form in the size and tint of the flowers.
Those of the ordinary humilis are pink, deeper externally than inside; in A. h. macrantha they are larger, with deeper colour, inside and outside purplish; A. h. purpurea has the large flowers of macrantha, with the outer scales deep purple, and A. h. rosea has large bright rose-coloured flowers. Macrantha and purpurea are the most effective varieties, and the most vigorous growers. Their culture is very simple: they grow admirably in a light rich compost made up of fibrous peat one part, and sandy fibrous loam two parts, giving sand liberally, more or less, according as it may be deficient or abundant in the compost naturally. The drainage requires to be good. Cool greenhouse treatment suits them best, with light airy position in winter. A cold frame, or the open air in an open but sheltered spot in summer, is preferable to the greenhouse; but they should be housed in autumn, before the rains drench the pots and destroy the roots. They are usually trained in the form of dwarf bush specimens, and, to my mind, this appears the most natural way of doing them; but variety of form is often necessary as well as pleasing, and may be obtained with comparative ease with these greenhouse everlastings.
They can be trained into the form of pyramids or dwarf standards with as much ease almost as a Fuchsia or Azalea, only stakes and tying are necessary in these styles in this case. For standards, a neat wire trellis of the umbrella shape is indispensable; but for pyramids only a stout central stake is necessary, for the purpose of supporting the main stem or stems, as it is better to be provided with two or three rather than dependent on one in case of accidents. The plant should be formed by pruning more closely above than below, allowing the central leaders to extend till the requisite height is reached, and taking care to have the sides equally furnished with laterals at all points. Plants not fully formed should not be allowed to flower much, if any, especially those intended for pyramids. They will the more quickly become enjoyable objects, if their energies are concentrated on growth for the first two years from cuttings, during which period shifting into larger pots and stopping the shoots should be carefully attended to in accordance with the rate of growth.
Large shifts should not be given at any time, and the new soil should be made rather firm as it is filled into the pots. "Well-established plants require to have the old shoots thinned out moderately annually, in order to keep up a supply of strong healthy laterals. No matter what form they are grown in, these when allowed to extend become weak and unmanageable, and yield small flowers in small numbers. They are easily propagated by cuttings of ripe but not hard shoots as early as they can be got in the summer. If the propagating house is not too airy no bell-glass is necessary. They are somewhat liable to damp, and if a glass must be used, it should be removed at night, or during part of the night and dull days. Sandy peat is most suitable for the cuttings.