i88i.] POTTING MATERIAL FOR ORCHIDS. 567 



were found to have plenty of roots, but they consisted of cast-metal 

 pegs, to steady the plants on the top of a sour mass of black peat 

 and small crocks. The soil, on being squeezed in the hand, came 

 through between the fingers something as soft grafting clay would. 

 This may be considered the very worst possible kind of material for 

 Orchids, and is happily not now used in many cases, if any. 



After trying a good many proportions of the fibre of the tough- 

 est peat and clean living sphagnum, mixed with charcoal and potsherd, 

 we have been induced to use less and less of the peat and charcoal, 

 and more of the sphagnum and potsherd. We grow somewhere about 

 thirty sorts of Cypripediums, and find now, beyond all doubt, that they 

 do best with us in nothing but sphagnum and crocks, using charcoal 

 lumps in the very bottom of the pot for lightness. Our objection to 

 charcoal in many instances is, that unless the watering be very care- 

 fully attended to — a matter not always easily guaranteed— it holds too 

 much water, and rots the roots. 



In the case of Odontoglossums, we have used, as a rule, about half 

 the fibry part of peat and sphagnum. But last season a few were 

 potted in pure sphagnum, and if there be any difference, we think it 

 is in favour of the latter, and we intend extending the experiment. 

 The same applies to Lycaste Skinnerii. 



For a good many years we potted our Calanthes in about equal pro- 

 portions of peat and sphagnum, with dry horse-droppings mixed, and 

 the bulbs of C. Veitchii often attained to the dimensions of a foot 

 or more in length, with bloom-spikes in proportion. Two years ago 

 we happened to be short of peat and sphagnum at the time of potting 

 them, and we used the somewhat orthodox mixture of turfy loam and 

 a little manure ; but two years of this material have, with us, brought 

 down the bulbs to very much less dimensions. And this season, when 

 they were in full growth, we were dissatisfied with their condition ', 

 so we shook them out of the loam, and repotted them in peat and 

 sphagnum, with the result that they improved every day afterwards. 

 No more loam in our case, therefore, shall be used for Calanthes. Yet 

 others grow them well in loam. 



We find also that the less of lumpy peat there is about the roots 

 of such as Dendrobiums nobile and thyrsifiora, the better they thrive. 

 The mere fibre of peat, sphagnum, and potsherd we consider much safer 

 material. Roots multiply and ramify more equally in the latter mix- 

 ture ; and when that is the case, and with plenty of water in the 

 growing season, the growth is more robust and clean. 



Frequent repotting may be regarded as an evil in Orchid-growing, 

 but where much lumpy peat is used it is a necessity, or rotten roots 

 will be the result as soon as the peat sours. But when rather small 

 pots than otherwise are used, with sweet fibre and sphagnum and pot- 

 sherds for potting material, and these get in possession of the roots, fre- 

 quent shifting is not necessary, and there is not nearly so much danger 



