The Garden Under Glass

POTTING AND POTTING SOILS 225 Peat, Moss and Fibre These I have grouped together chiefly because they answer in many respects the same purpose—that of re-taining moisture. None of them are of any great fertilising value, but for their mechanical action they are in great demand. The great drawback to the use of peat is that it has a tendency to go quickly sour. This is especially the case if the dusty portion is not eliminated. For use I should advise that it be broken up, so as to exclude most of the dust. The dust may be used for putting on the out-side garden, especially near rhododendrons; but on no account should it be used for any purpose under glass. Where peat is largely used in a compost the soil will be more difficult to mix, on account of its so hanging together. It is used chiefly for orchids, azaleas, ericas and rhododendrons. Sphagnum moss, which is found in boggy woods, is the only kind which can be induced to keep alive in a compost. For this reason it forms a large part of an orchid soil ; for, besides thus retaining more moisture, which the orchid will appropriate, it serves as an indication of the need of water. When on the top of the compost the moss heads show themselves freshly green there is sufficient moisture ; but if the green be of a pale colour, approaching whiteness, then water will be needed. Cut off the bottom ends of the moss, using only the top two inches, or chop the moss into fine pieces. In either case weeds should be taken out. The fibre mentioned is the refuse from cocoa-nut fibre. It is not greatly used for potting, though often for plung-mg plants, and for striking cuttings. I have, however, found it useful for mixing with leaf-soil and loam for form-ing a seed compost. For starting bulbous plants it is also p