The following is an extract from Alpine Flowers for English Gardens by William Robinson and published in London by John Murray, Albermarle Street in 1870
(Ed: I have corrected a few original typing/printing errors and introduced emphasis where helpful).
Part I – The Rock Garden (pages 24-26
Popular and almost universally cultivated as hardy ferns are, however, it is not at all common to see some of the most noble and interesting of them – The Royal Fern and several other Osmundas – otherwise in a shabby, or at best in a half-developed, condition.
Mr A Parsons, of Danesbury, a well-known florist and cultivator of ferns, has overcome this difficulty, and narrates his marked success in the pages of the ‘Florist and Pomologist’ [fruit grower].
He formed a very large fernery in an old chalk pit, and with much success; but notwithstanding all the care taken of the Osmundas and allied ferns, they were tried for four seasons with no satisfactory result, the roots of the surrounding trees robbing them of both soil and water.
“A change was then made: a piece of ground, of irregular shape, large enough to contain about twenty plants, was staked out, and the mould, or more correctly speaking, the chalk, was removed to the depth of three feet; a bricklayer followed, and put in a floor of three bricks laid on the flat, set in good Portland cement, and over this a layer of plain tiles, the sides being made up to the ground level with a four-and-a-half-inch wall, well built up in the same kind of cement; this made the whole water-tight, and prevented the roots of the surrounding trees from penetrating and robbing the ferns of their moisture.
The space was filled up with earth, compounded of good loam, peat, and leaf-mould, in equal proportions, with about one-fifth of good rotten manure added thereto; these ingredients were thoroughly mixed and well trodden in, and then the ferns were planted.
In forming this bed, provision was made for the escape of the surplus water, by introducing into the front wall, at about four inches from the bottom, a common three-inch drain-pipe, which communicated with a small tank, about three feet square, sunk into the chalk, so that all waste water became absorbed. This method proved to be eminently successful, the plants far surpassing in size any I have ever seen under artificial cultivation and judging from report, rivalling their growth in their natural habitats.
Last season I could boast of Osmunda regalis with fronds at least eight feet in length, Osmunda spectabilis four feet and a half, Osmunda Claytoniana five feet, Osmunda cinnamomea three feet and the beautiful Osmunda regalis, var. cristata, three feet in length. Adiantum pedatum grew from two to three feet in height, and others were proportionally fine. The plants were not drawn up by being planted closely together, but were placed at a fair distance apart, and became handsome and noble specimens.
Every spring, I apply a dressing of about two inches of rotton manure to the surface, and just cover it with mould for the sake of appearance. This artificial swamp is the admiration of all the visitors here. The plants are always in a healthy and vigorous state, and have none of that half-starved appearance so frequently to be seen. The result of my experience induces me to believe that a more liberal treatment would not be found objectionable in the cultivation of many more of our native ferns.
I intend making the experiment this season, and may possibly find time to make known what amount of success I may meet with. In concluding my remarks upon which I may term ‘growing Osmundas under difficulties’ I would observe that the points to be principally attended to are:
- A deep water-tight and root-tight tank, the depth of which may, with advantage, be more than in the case I have described
- A rich nutritious soil
- An abundant supply of water
- A drain to carry off the surplus.”
Even the rare Killarney fern, usually kept in houses may be grown successfully in a cave in the rock-garden ….