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.
No one doubts that fine-foliaged plants have wonderfully progressed in public estimation during the past few years, and it may be fairly interpreted as a certain sign of the increase of good taste in this country. Of these plants, the Tree-ferns form a grand tribe, and with noble proportions of growth there is always found in happy combination - elegance and grace. Their fine graceful habit and singular distinct appearance render them peculiarly adapted for conservatory decoration or other purposes. As many as twenty-four, at least, fine forms of these Tree-ferns are in cultivation, from the magnificent Tree-fern of New Zealand (Dicksonia Antarctica), with its immense spreading fronds and gigantic stem of from 4 to 10 feet in height, down to smaller forms, on stems from 1 to 2 feet in height. Of the genus Alsophila there are some ten fine species. Of these the most ornamental are A. aculeata, or ferox; A. australis, A. Capensis (remarkable for having abnormal growth, and clothing the upper part of the stem in a curious manner), A. excelsa, and A. Latebrosa. Another grand and noble Tree-fern is Cibotium princeps, with its noble spreading arched fronds.
Perhaps nobler still are the grand species of Cyatheas, such as C. arborea, C. medullaris, C. serra, and C. Smithii.
Reference has already been made to Dicksonia Antarctica; and equally remarkable, and of similar noble proportions, are D. arborescens, D squarrosa, and D. Youngii. Another most distinct and curiously grand Tree-fern is Hemitelia Horrida, possessing a truly graceful appearance, from the slender head supporting spreading heads of immense light-green fronds of smaller growth. But not the less elegant are the Lomarias, particularly L. discolor, L. Gibba (a most beautiful and graceful Tree-fern, of small but handsome growth), and L. zamaefolia, a very interesting form. Lastly may be enumerated the beautiful Todeas; Frazerii, and Pellucida, requiring a moist, close atmosphere, but very beautiful when well managed.
For conservatory decoration the Tree-ferns are peculiarly adapted; and as they can be had of such varying proportions as to suit alike the most spacious as well as the most unpretentious of buildings, their value is greatly enhanced. For small conservatories the beautiful forms of the Lomaria are specially adapted.
The soil best adapted for Tree-ferns is a compost formed of peat, loam, leaf-mould, and sand. Such a mixture is used at the Royal Botanic Gardens, Kew. The ingredient should not be sifted; but the peat and loam, which should be fibrous, chopped into small pieces. The leaves should be used when only half decayed, chopped fine; for by using them before they reach the last stage of decay they are not so liable to render the compost too close in texture, and they are just as capable of nourishing plants at that stage as afterwards. Free drainage is indispensable; no class of plants suffer sooner from stagnation than Ferns, and none require more steadiness in the supply of water. If they are allowed to get dry, so that the fronds "flag," in nine cases out of ten they never rise again. - Thomas Sampson's Seed Catalogue.