This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
An Address By John Robinson, Before Essex Institute. Salem, Mass Fern cases, or ferneries, as most of us call them, were originally called Wardian cases, in honor of their inventor, Dr. B. N. Ward, of London, who published a book upon the subject in 1842. These cases are only a modification of the hand-glass always used to force or protect plants in the greenhouse or open air; yet the placing of this in a practical way renders it easy to import the plants of foreign tropical countries, which otherwise could never be seen here in a living state, besides enabling us to grow at home as beautiful ferns and other delicate, moisture-loving plants as are seen in the hot-house or conservatory.
The fern case, as it comes from the cabinetmaker's, is a handsome piece of furniture, but an expensive one - so expensive, perhaps, as to deter many from possessing a fernery. This need not be, for at home a case can be made just as serviceable, and having some advantages even over the expensive ones.
Procure from your carpenter a good pine board of the dimensions you may wish, for the base of your structure, which by the way should be about one-third longer than wide. Next obtain a suitable molding (black walnut is the best), and fit it around the base-board, as if it was a picture-frame on end. Next have a zinc pan made to fit closely inside of this, coming up to the top of the molding. Do not have any turned-over edge or ring to the pan, as they are of no use; neither should the pan be made first, as it is difficult to make a neat box to fit outside it. Have the pan painted on the inside with a good coat of tar, as the delicate roots of the plants dislike to come in contact with a metal surface. Next comes the glass; and here is where most persons mil. Be sure the glass is inside the the pan, and never have the pan inside the glass, for the moisture collecting on the glass runs down outside the pan to the woodwork, rotting it, and very likely between the moulding and base-board, on to the table or what else the case rests on, causing much trouble.
Also in watering, the glass directs the water in like manner, with the same if not worse results.
A good proportion for the glass is to have it as high above the base as the case is wide, and it should go to the bottom of the pan. Have the corners true and the top level, that the plate of glass which covers the top, and which should be one-fourth of an inch larger all around, shall be even. With common flour-paste attach narrow strips of cloth up over the corner angles on the outside, but only an inch or so down the inside from the top. When dry, paste some dark paper over it, so as to cover the cloth, also around the top plate of glass, to prevent the edge from cutting your hands. No cloth is necessary for this. Fill and oil the black walnut moulding, and the case is complete.
A still more simple one is to tar the inside and paint the outside of a shallow pine box, and place the glass directly inside it. If you intend purchasing a handsome case, it will be better to have one made to order, as all the ready-made ones usually offered for sale have the case poorly and incorrectly constructed, in more ways than one. Nearly all have flat tops, to be avoided where there is woodwork (the home-made case having no woodwork at the top, it is not a disadvantage). One advantage possessed by the expensive case, is that the whole top takes off, enabling you to work all around, and not entirely from overhead. Here you may construct ruins, grottos, arches, etc., with pumice and cement. Pumice is so light that it adds but little weight to the case, and the cement will bind the whole together as firmly as one rock, all at a very slight expense, at the same time adding much to the beauty of the interior. Very neat circular cases are for sale at the stores, and can be filled so as to be very attractive. They can also be used as fern nurseries. To do this, make the earth damp and firm on top, having first placed a few small pieces of broken flower-pots in the upper soil.
Take a leaf of some fern, or several different species of ferns, if you desire, that have the fruit quite ripe This can be discovered by shaking over white paper, when, if ripe, a brown powder will come off. These are the spores or seeds. Dust these over the prepared earth, replace the glass, and leave the case in a warm, shady corner. In a few weeks, if not permitted to become dry, a green scum will appear, which in time will transform itself into the most beautiful little ferns, that may be separated, potted, or transferred to other cases.
Now, to fill the case. First make, if the pan be three inches deep, about one inch in depth of drainage - pebbles, charcoal, broken bricks, or, better still, broken flower-pots; over this a thin layer of moss or coarse, fibrous stuff of some sort, to prevent the earth washing into the drainage and choking it. Some cases have holes in the bottom, and glass receptacles for superfluous water; but, if care be used in watering, this will be entirely unnecessary. For soil suitable to grow most plants likely to be in the fernery, a mixture of one part sand, one part peat, two parts light pasture loam (leaf-mould may be used for peat), will do well. The earth should be heaped up a little in the center, or, if the case is large, two or three little elevations may be made. Upon these place the larger ferns or plants, with the others distributed around them. A log of wood covered with moss and small ferns is a very pretty center piece; and to cover the ground the little running Selaginella, common in all greenhouses, answers better than almost anything else, except our own native mosses, which must be treated with care, or else they mold or dry up.
Ferneries may be divided, if you like, into two classes - dormant and active. By dormant I mean such as contain plants which lie at rest during the winter months - chiefly our natives and others like them in habit that have been introduced. These it is well to arrange separately, as they require less heat than the species growing all the year round, chiefly from the tropics, which form the active fernery.