A variety of opinions have recently been advanced regarding what is the best potting material for Orchids in general. Mr Bruce Finlay, of the Manchester Botanic Gardens, has recently recommended, from his own experience, that Cattleyas are likely to do best in crocks without admixture of soil of any description. In reference to this suggestion, other noted growers have maintained that some peat should be used with the crocks. A writer in a contemporary lately recommended that no peat should be used for the majority of Orchids, but only sphagnum and potsherds and charcoal. No doubt, in the growth of a good many genera, a happy mean between these rival systems has been found most satisfactory.

We believe, however, that, as a rule, Orchid-growers use much less peat now than they did twenty years ago, and are more particular as to the texture of what they do use. There is one point on which we believe all are quite agreed, and that is, that the less peat there is in an Orchid-pot unoccupied with roots, the more likely is the potful of material to remain sweet and wholesome, and the plant itself healthy. A few years ago a lot of Orchids came into our hands that had been potted with a liberal admixture of peat, evidently without having the finer portion separated from the fibre. On turning out the plants they 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 toughest 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 carefully 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 proportions 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 thyrsiflora, 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 mixture; 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 potsherds for potting material, and these get in possession of the roots, frequent shifting is not necessary, and there is not nearly so much danger from over-watering. To have a surface of living sphagnum is a factor of considerable importance in keeping the material sweet, and in giving warning when water is needed, especially in the case of such genera as Cypripediums and Odontoglossums.

Many years ago Mr Turnbull of Bothwell grew some specimens of certain genera of Orchids, such as Miltonias, to the greatest perfection we have ever seen, and the potting material was chietly the tough roots of Luzula maxima, which plant, to the best of our recollection, Mr Turnbull top-dressed with leaf-mould, to encourage it to make masses of fibry roots for potting with.