114 THE FERNS AND 



constructed, it matters little what sort of stone or other material is 

 used, so long as it is of a porous nature ; and the taste of the culti- 

 vator must decide what form it is to assume. An excellent way 

 of growing ferns is to make a raised bed, from 1 to 2 feet high, of 

 porous stone, broken bricks, or similar materials, filling in the 

 interstices with smaller fragments, and covering the whole with a 

 few inches of soil, which should not, however, exceed six inches in 

 depth for the smaller species, or a foot for the larger. A layer of 

 spliagnuni moss above the stones aids materially in draining, and 

 prevents the soil from being washed rapidly down among the stones. 

 If peat can be readily obtained, a quantity of it may be broken into 

 small pieces, and similarly used for filling up the interstices of the 

 stones, before spreading the soil on the surface. Such a bed, placed 

 on the south side of a wall or building of almost any kind, will prove 

 very suitable for all the hardy ferns. Next in importance to the 

 drainage is the kind of soil employed. This should be light, and 

 yet capable of being made quite firm. It is needless to give 

 absolute rules for the preparation of such a soil, and nearly each 

 successful cultivator has his own favourite compost ; but a mixture 

 of equal parts of well-broken peat, loam, and sand will be found 

 most generally suitable. Manure of any kind should not be used ; 

 but an excellent loam may be got by allowing old turf from a 

 meadow to decay for a couple of years in a heap. The sand, also, 

 should not be too sharp ; sea-sand, thoroughly washed free from salt, 

 is very good. But here, again, observation of the natural habitat of 

 the fern must guide the cultivator. Some of the GleicJienias will be 

 found to luxuriate in a mixture of sand and peat, or even sand alone; 

 while many of the larger bush-ferns grow in deep, heavy loam. 

 Species of Pteris, again, often root strongly in clay banks with a 

 minimum of loam. So that in planting the various kinds, more or 

 less of the constituent parts may be added to the soil, as is thought 

 desirable. Where manageable, it is a good plan to have the soil for 

 a fernery baked before using, by subjecting it, in a moist state, 

 to a heat about that of boiling water. This process destroys vast 

 numbers of fungus spores and seeds of weeds, at the same time 

 freeing the ground of insect pests. This should always be done with 

 soil to be used in a house, but for the outdoor fernerv it is not so 



