CULTIVATION. 
377 
and syringing, the latter being the only remedy for 
the black mildew. 
This concludes my observations on pot-cultivation, 
and in order to save repetition, it must be understood 
that the process as regards soil, watering, airing, &c.> 
is equally applicable to natural cultivation, which I 
now proceed to describe. 
HE natural cultivation of Ferns consists in growing 
them without the aid of garden-pots. This is 
accomplished by placing them, as far as artificial 
appliances will permit, under conditions and influences 
analogous to that of their native wilds ; for that 
purpose uneven irregular surfaces are best adapted, 
whether natural or artificially formed ; and as FerUs- 
are generally called rock-plants, which many truly are, 
therefore, in order to imitate rocks, the surface on 
which they are grown is made irregular and covered 
with rude stones, on or between which the Ferns are 
planted; hence the term Rockery is applied to this 
kind of cultivation. 
For all species of Ferns, either hardy or tender, 
this system of culture, which admits of them being 
planted out, is far preferable, to whatever extent it 
may be desirable to practise it, whether in the sheltered 
nook, in the open air, or in stoves or greenhouses, 
either partially or entirely devoted to it. For by it is 
the finest health imparted to the plants. The rockery 
bank which once occupied the Temperate Fern House 
at Kew, together with the fine fronds of tropical species 
grown on rockery in the Palm House, afforded excellent 
III. Natural Cultivation. 
