ORCHIDS FOR AMATEURS.

Otago Daily Times, Issue 21214, 20 December 1930, Page 7

ORCHIDS FOR AMATEURS.

STARTING A SMALL COLLECTION. Througout the length and breadth of this country there are thousands of greenhouses, many of them on the small side, that are at present devoted to a miscellaneous collection of plants, which, to put it mildly, are anything but a credit to the owners. There is a tendency towards trying to accommodate too much of a mixture of plants requiring different conditions, instead of choosing a group which can he made perfectly comfortable in the house at disposal. Temperature again plays an important part, and before making any choice, the heating capacity during an average winter must be taken into consideration. Orchids deserve consideration from amatuers and owners of moderatelyheated greenhouses. It should be fully understood that they are quite as easily grown as the usual run of greenhouse plants. Moreover, once having obtained an orchid, it can be kept in good health and increased by division, whereas many greenhouse subjects need renewing from time to time either from cuttings or seeds. There is also less labour with orchids in regard to potting, and this in an average collection is spread over the greater part of the year. Although the orchid family is a large and varied one, it eau, from a cultural standpoint, he divided into two sections, one of which is generally known as cool growing, and the other as, warm. It is hopeless to attempt the growing of both groups in the same house, hut the difficulty is often got over by dividing a large greenhouse into two divisions. One near the boiler is usually fitted with a few extra pipes, when it is rendered suitable for growing warm house orchids, and' the other division is devoted to cool subjects, there being fewer pipes. If a night temperature of 55deg can he maintained, warm house orchids are recommended, hut when the thermometer falls as low as 45deg, or even 40deg, on a very cold night, then cool house orchids should he chosen. When ordinary green, house subjects have been grown, a few minor and _ inexpensive alterations may be needed in the interior of the greenhouse. The ordinary wood stage is covered with builder’s slates or sheets of corrugated iron, upon which is placed a layer of gravel, ashes, or coke breeze. A gravel or ash path is better than tiles, because orchids enjoy a more or less moist atmosphere, but much useful information upon this and other phases of orchid culture could be gleaned from a reliable book dealing exclusively with orchids.

The old idea that orchid plants are expensive must be ruled out at once; prices compare very favourably with any other occupants of the greenhouse. The first step is to get in touch with an orchid specialist, such as a representative of a firm making a feature of these plants. I do not advocate buying sufficient plants to fill the greenhouse at once; the better plan is to purchase a dozen or so, which could form the nucleus of a collection that in time may easily become remarkable for the quality of the plants rather than quantity. Having made start, it will be much more interesting to secure an occasional specimen in bloom, and with increased knowledge the amateur will be able to discriminate and obtain only those varieties that have some particular feature to commend them. In such a way many famous collections have been built up. The beginner himself must decide the question whether he will grow cold or warm house orchids, a fact that is governed by the amount of heat at command. If the decision is in favour of warm house orchids, a. suitable dozen be as follows :Two brasso-cattle-yas, six cattleyas in variety, two cypripediums, and two cymbidimna. Collections of good, useful, easily-grown orchids can be purchased for two or three guineas. With many the cypripediuma are an acquired taste, but they embrace some really beautiful flowers and are remarkable for the length of time thein blooms maintain their charms. The house could very well be stocked with cattleyas and their allies, which embrace laclio-cattleya, brasso-cattleya, sophro-cattleya, and hrasso-catt-laslia, and. one or more would be in bloom the greater part of the year. Some greenhouses arc rather lofty, and such would be suitable for a collection of cymbidiums, with one or two of the tall-growing cpidondrums to add a little variety. GENERAL CULTURE HINTS. The main cultural requirements are as follows: Blinds will be necessary during. the spring and summer months, and often in the early part of autumn, whenever the sun is bright. Attention to shading is more important in spring, after the dull winter months, than in autumn, when the plants are more accustomed to strong light. The minimum night temperature in winter is about 55deg, with a rise of sdog or so by mid-day, but if many degrees of frost are experienced, it is better for the thermometer to register a few degrees lower than employ excessive fire heat, which produces a dry, arid atmosphere that is injurious to most plants, orchids

included. Always use rain water for watering and spraying purposes, and it should be nearly the same temperature as the house. For damping the floors, stages, walls, use tap water. With ordinary observation, and studying each plant, the art of watering will soon be acquired. When a plant is growing and rooting freely, the soil must be kept moist, but after growth is completed, a less quantity of water will suffice. Enough, however, should be given to keep the pseudo-bulbs from shrivelling. Annual repotting is not necessary, and such work ought only to be undertaken when new roots are pushing out from the base of the new growth. Each pot should be filled one-fourth of its depth' with drainage, over* which is placed a layer of osmunda fibre. This fibre will also form the bulk of the rooting medium, to which is added a sprinkling of chopped sphagnum moss.

A more or less moist atmosphere is needed, and the amount of damping down will depend on the, weather and period of the year. During the winter less atmospheric moisture is required, also on days when there is little ventilation. When the weather is bright, and the ventilators are open an inch or two for several hours, damping down may be necessary two or three times, but, as a rule, twice each day, morning and afternoon, will he sufficient. During a hot period a light spray overhead will be beneficial, ' but it ought always to be done sufficiently early for the foliage to dry before sunset. Whenever affording ventilation, avoid cold currents of air passing' over the plants, and to achieve this object the top ventilators only need to be used, unless there are any ventilators in the brickwork of the greenhouse. COOL ORCHIDS. Thera will, of course, be some amateurs who can only command a moderate temperature in winter, also others whose greenhouses have a north, west, or northeast, aspect. Such structures are ideal for the succcessful culture of cool orchids, and the following could very well form the beginning of a collection of showy and very floriferous plants: Oncidiums, sophronitis, masdevallias, a. few of the cymbidiums, miltonia, Cypripedium inaigne, odontoglossuma, and odontiodas can be included in a cool house collection, but for a beginner I would recommend the odontoglossums and the odontiodas. Here will be found ample variety, and of the odontoglossums any of. the following are sure to give satisfaction: O. amabile, crispum, eximium, ' Lambeauianum, percultum, Vuvlstekei', Eolfete, and Jasper, while the odontiodas could be represented by Bradshawias, Lambeauiana, Vuvlstekese, and Charleswortbi.

The general culture is somewhat similar to that detailed for warm orchids, but a fundamental difference is the temperature. Here it may fall to 45deg in winter, and during the summer months it will be kept as near COdeg as is pos-' sible fay judicious ventilation and use ob blinds.—T. W. Briscoe, in Amateur Gardening.”