July, 1914.] 



THE ORCHID WORLD. 



237 



DENDROBIUM CULTURE. 



TilE fact that good culture is absolutely 

 essential to produce the finest flowers 

 is now fully recognised, and Dendro- 

 biums are no exception to the rule. One of 

 the secrets of success is the maintaining of 

 healthy vigorous stock, and so long as this 

 can be accomplished the grower need have no 

 fear concerning the flowering results. 



Although Dendrobes are not quite so 

 popular as they formerl)- were, it may be only 

 an interval in their fashion, and before long 

 they will surely regain their lost popularity. 

 Many collections include old specimen plants 

 which are thoroughly worn out, and no 

 amount of skill and labour will bring them 

 back to health. The only means of saving 

 the varieties is to select healthy portions and 

 start them on a new lease of life by means of 

 suitable culture. 



On the majority of old plants there can be 

 found several young plants growing out of 

 the nodes of the bulbs, and these should be 

 carefully removed along with a few inches 

 of the old stem, and placed in small pots 

 with a light compost. The portion of the 

 old stem supports the young growth until 

 it makes roots and has its own existence. 

 Plenty of heat and moisture — in fact, it does 

 not seem possible to give too much — are 

 necessary to ensure rapid growth. In the 

 course of a few weeks' treatment a rapid 

 extension of the young plants can be seen, 

 and at the conclusion of the growing season 

 some nice sturdy plants will be acquired. 



Some varieties are not so free in producing 

 young growths, and with these it will be 

 necessary to select unflowered portions of the 

 old stems, which should be cut in lengths of 

 two or three inches and placed round the 

 edge of a pot in which only sphagnum moss 

 is inserted. This allows the resulting young 

 growths to be formed in a natural and upright 

 position, and is a better method than simply 

 laying the old liulbs on a bed of moss. 



It is during the following season that the 

 young plants, after being carefully wintered, 

 will make raj)id growth. The second year's 

 bulb is often four or five times taller, and on 



some occasions reaches an astonishing height. 

 Plenty of atmospheric moisture and syringing 

 of the plants on all fine days is necessary to 

 produce stout bulbs of a robust nature. 

 When the plants have nearly completed their 

 season's growth care must be taken to see 

 that they do not attempt the formation of 

 another bulb, for if this occurs the flowering 

 results are not so good, while the appearance 

 of the plant is spoilt. It is generally possible 

 to tell when growth is nearing completion, the 

 newly-formed bulbs taper to a point, and form 

 a single leaf at the apex. 



At the end of the growing season water 

 must be gradually withheld, both at the roots 

 and in the air. A light and airy place should 

 be selected for placing the plants — on a shelf 

 is a good position for the smaller ones — while 

 the amount of ventilation should be gradually 

 increased. There is much more in this final 

 treatment than many amateurs suppose. As 

 soon as the plants are affected by drier 

 conditions they at once attempt to gather 

 further nutriment by the formation of new 

 roots. The roots break out from all parts of 

 the primary roots, and not only work their 

 way through every portion of the compost but 

 reach right over the pot in search of additional 

 food. The jjlants seem to know that winter 

 is coming, and the bulbs swell rapidly and 

 attain a considerable degree of ripeness. 

 Without the drier conditions no such activity 

 commences. 



Winter treatment consists in keeping the 

 plants just moist enough to prevent much 

 shrivelling of the bulbs. If the conditions are 

 too cold and dry the beauty of the flowers is 

 spoilt, although the plants themselves may 

 not suffer any perceptible harm. Yet care 

 must be taken to prevent too humid and warm 

 a temperature or many of the buds will 

 become vegetative growths instead of bloom. 

 Experience in this matter is of considerable 

 advantage, but with Dendrobes one can make 

 many small errors in their treatment without 

 greatly spoiling the final results. This is 

 saying more than can be said with some 

 species. 



.S]:)eaking generally, Orchids will not stand 

 much forcing. But with Dendrobes there is a 



