CHAPTER IX
MANURES FOR ORCHIDS
It should be distinctly understood that, in the case of true epiphytes, there is no need for manures, and, that artificial chemical manures are almost certain to bring about disastrous results, the final collapse being in proportion to the potency of the stimulant used and the recklessness of the grower. Where rain-water can be obtained and stored for use throughout the season, it is safest and most satisfactory to rely on this alone, except for some terrestrial Orchids. The chief difficulty in recommending the use of manures for any class of plants, Orchids especially, is in the fact that, once the practice is commenced, even those cultivators who begin cautiously frequently lose discretion in the course of time and ruin their plants by excessive applications. It is for this reason that the growers of plants for market purposes, whose secret of success almost entirely depends on the use of manures, are careful to give out the supplies to the men who have to use them, or, with the very best intentions, they would often destroy a crop. Indeed, it is not uncommon for foremen, or men in charge of departments in large nurseries devoted to growing plants for market, to resort to unfair means to get extra supplies of manure for their plants, and frequently with bad results. There is another curious feature about the use of manures in market-plant gardens, namely, that all concerned observe the greatest secrecy in the matter, and rarely admit that they use "anything but water"—that being the common expression. The same secrecy is observed by the Orchid expert in most cases. Another thing is that there is no common formula accepted by all practitioners. Each seems to have his own opinions as to materials, quality, and strength of the stimulants used.
One thing is certain, that even where artificial manures are used, the time of application and its discontinuance has more to do with success or failure than the nature of the manure itself. Even in cases where the administration of a mild stimulant is of use during the period of active growth and free rooting, if the manure is not discontinued after growth is completed much mischief is done.
It is not necessary to go into the relative merits of chemical manures, which are not recommended for use, but it may be stated that some growers do use small quantities with apparently good results, restricting the use of the manure to the active growing season and during the time the flower-spikes are forming. Aërides, Saccolabiums, and Vandas seem to be exceptions, as they represent the highest development of the epiphyte. Odontoglossums and some similar Orchids have been treated to a very small quantity of Peruvian guano sprinkled in the water used for watering them in spring while the flowers were forming, and without a bad effect; but the quantity used was very small, and the water was not allowed to touch the leaves or pseudo-bulbs. One grower on the Continent was in the habit of sprinkling a handful of nitrate of soda in the gutter of the house, especially before, or during heavy rain, in order that a little solution of it might be carried into the rain-water tanks in the Orchid house. His plants throve well, and this shows that even with epiphytal Orchids there is a field open for experiment; but the operator must not lose sight of the fact that he is "playing with edged tools." We will now state what has been proved to be beneficial when carefully carried out. Those who grow batches of the showy Dendrobiums such as D. nobile, D. Wardianum, D. Phalænopsis, and others of the class, and who, at the growing season, place them in a warm, moist house, suspended from the roof for preference, frequently give them weak doses of liquid manure during the season of growth, and the plants make very fine growth.
PLATE IV
CATTLEYA TRIANÆ
Var. "Hydra"
(The plant bore 88 flowers.)