PROPAGATION BY DIVISION
It used to be thought a very delicate operation to divide an Orchid, or to remove any portion of it for the purpose of obtaining another specimen, and, when the operation was carried out, it was thought to be at the risk of the plant and its offset.
In the case of badly grown plants, or where the houses are unsuitable for growing Orchids successfully, there may still be considerable risk in the process; but under ordinary conditions, and where the plants have proper accommodation, there is no risk whatever; it may be said that plants are never in better health than when they are divided at reasonable intervals. If we consider the case of Cypripedium insigne Sanderæ, some of the white Cattleyas, and many other Orchids which were imported only as single specimens originally but which are now well represented in gardens, the advantage of dividing the plants is readily seen.
Pseudo-bulbous Orchids with progressive rhizomes, such as Cattleyas, Lælias, Oncidiums, and Odontoglossums, should be divided by severing the rhizomes, retaining two or more pseudo-bulbs together. This operation can be done at any season of the year, but it is most convenient to do it at potting time, and, for preference, just before the commencement of the natural growing season of the plant. Small pieces should be placed in small Orchid pans or baskets, but larger ones may be potted at once and placed on the stage with the other plants.
Dendrobiums may also be propagated by dividing the plants, but a large section of the genus may also be propagated by cuttings of the pseudo-bulbs. This method is specially useful for increasing a rare and fine variety of Dendrobium nobile or others of the section, as a good supply of plants can quickly be obtained in this way. The method is to cut the pseudo-bulbs into lengths of two or three inches and to place them in small Orchid pans, six or eight in a pan, suspending the pan in a warm, moist, house. The Thunia section of Phaius, Epidendrum radicans, and some other Epidendrums and Orchids of similar growth may be multiplied in this manner. Further remarks on propagation will be found under the names of the genera enumerated.