FOLIAGE PLANTS FOR GREENHOUSE 81 



root action is over-potting and using too deep a body 

 of soil in the pots. A good depth of soil may be 

 suitable for some of the strong growing Pterises, but 

 for delicate Adiantums and all ferns that spread them- 

 selves by creeping rhizomes it is especially wrong to 

 pot or plant in a big body of soil, for with these the 

 soil is merely a medium through which the necessary 

 moisture is conducted to the plants, and if too much is 

 used it is soon rendered unfit to perform its office and 

 the roots die out and are not replaced. As a proof of 

 this, one may frequently find in ferneries plants refusing 

 to grow in elaborately made but too capacious pockets, 

 while fine plants of the same varieties may be found 

 growing well out of the merest crevices into which a 

 rhizome may have chanced to escape, or a spore to have 

 germinated, providing the position is such as to allow of 

 a bountiful water supply. 



All potting operations should be carried out in spring 

 just as the new fronds of the year are about to appear, 

 for at this time the roots are fully active or will soon be- 

 come so, and consequently the new soil is the sooner filled 

 with roots. At the same time, if increase in number 

 is desired, the tufted ferns may be split up, taking care 

 that each division is well provided with crowns and with 

 roots, so that each will soon make a good and shapely 

 plant. 



The soil used in potting may be half fibrous loam, 

 broken up as roughly as it can be used, with leaf mould 

 and peat in equal proportions, and with the whole should 

 be freely incorporated finely-broken brick, charcoal, or 

 some other porous material, and a liberal amount of silver 

 sand. 



Most greenhouse ferns may be raised from spores, the 

 operation being a somewhat delicate one. Shallow pans 

 should be half filled with crocks, and on these should be 

 placed a very thin layer of the more fibrous and lumpy por- 



