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.
During the last quarter of a century, Ferns have become very general favourites in the decorations of rockeries, in many odd corners, under trees, and by waterfalls, where they can have a regular moist atmosphere, distilling its sweet and refreshing influences around them. In such situations how freely they grow, and develop their graceful forms, arresting the attention of every person who has an eye to beautiful form ! Even in the smoky town, how often do we see some of them, in small glass cases, placed in the windows, as we pass along the streets, and how very interesting they are to the tender and often delicate hands that attend them! Some Ferns thrive very well in such situations. Many of our British Ferns are too large for growing in small cases in a parlour window. Still we have seen a few very good selections for such a position, and, when anything like well managed, they give a pleasing interest to a parlour window. I will here name a few of those I have selected for such purposes, and when they are taken while young, they will suit very well for a few years; and they are by far better suited for planting into glass cases while they are young than when they are old, because all their roots are close to the heart of the plants, and are, moreover, free of any decaying nature in their centre, and are more easily covered with soil, and they accommodate themselves farbetterto their natural condition and habitation.
One error we have often noticed in the management of such cases has been the tendency to keep them shut up too closely. By all means keep the dusty air of rooms entirely from them; still there is a difference between doing so and that of shutting them entirely off from all external air. Tropical Ferns, of course, require to be more closely nursed than British ones. However, whether British or tropical, it is always well to shade them from the hot sun during the middle of the day in summer. This can be done by throwing a thin shading over the glass. It will depend much upon the size of the case what selection of Ferns is most suitable to put into it; and it is very advis-ble that there be ample means of drainage, so that all unnecessary moisture can pass freely off. Stagnant tainted water is at all times to be avoided even with such moisture-loving plants as Ferns. For this purpose, we have used for the bottom of cases a perforated sheet of iron, or a board having plenty of holes bored through it; and then, underneath this perforated bottom, have a case or pan of tin or zinc. In the larger cases this can be made to be movable at pleasure.
In the case of globular glasses of 12 or 18 inches diameter, the receiver of all over-moisture may be made like a common saucer to sit under the glass, and when it is necessary to remove the moisture which has passed from the glass case, it is best to lift the whole out from the pan. In the selection of Ferns for cases, it may be well to bear in mind the habitats of the various Ferns, in other respects most suitable for this purpose. For instance, those found growing in shady or partially-shaded situations may prove more suitable than those found growing on the top of old stone-and-lime walls, or on very dry banks, fully exposed to all the dry influences of sun and air; and yet some of those found growing in such situations, by their very distinct forms, are very interesting, and give variety. Although we mention these peculiarities as belonging to different species, no doubt every one may suit their own individual tastes in their selections. However large or small any case may be, there should be in it a plant or two of Adiantum capillus veneris (Maidenhair Fern, commonly called), Athyrium Filix fcemina (or Lady Fern) - the younger these are the better - and some of the different forms of Lastrea Filix mas, Lastrea dilatata, Lastrea thelypteris, and Lastrea oreopteris, or Lastrea montana; or some of the common Polypodium vulgare, and the Scolopendrium vulgare, are very interesting in cases.
Adiantum nigrum is a pretty variety; but as it likes a dry situation, it may not answer so well; and yet I have seen one large plant of this variety of British Fern look well under cultivation. In this case, as in many instances, much depends on the position, and the skill of the cultivator.
It is very interesting to see what use some persons will make of very common things, and Ferns are capable of being turned to many useful and interesting purposes. Some few years ago, on my visiting a gentleman's dairy, this train of thought was forcibly presented to my mind on seeing a very noble plant of the common Scolopendrium occupying a very prominent position in that dairy. The dairy-room, where the milk was all displayed in pure white pans upon shelves of blue slate, is 16 by 20 feet, having a floor of red paving-tiles, all kept scrupulously clean. In the middle of this dairy was a small round table and pedestal of pure white marble, upon which was placed an ornamented pot, and growing in it was one of the largest and best plants we have ever seen of the common Scolopendrium vulgare, and well it looked in the midst of such a clean and well-ordered dairy. There were well on for five dozen fronds in this plant; the greater part of them were over 18 inches long, and as they fell gracefully over towards the white marble, concealing the pot, they presented an effect which was at once novel and very pleasing.