September, 1915.] 



THE ORCHID WORLD. 



269 



Oncidium corynephorum. 



Royal Horticultural Society by Messrs. 

 Sander and Sons, May 23rd, 191 1, when it 

 received an Award of Merit. O. Leopold- 

 ianum was exhibited by Mr. H. S. Goodson, 

 of Putney, July 28th, 1914, and obtained a 

 similar award. Our illustrations, reproduced 

 from the Society's Journal, show both 

 examples. 



CULTURAL NOTES. 



THE sun is gradually losing its power, 

 and shading on all but the cool 

 houses should be reduced accord- 

 ingly. Where roller blinds are erected their 

 use can be regulated as required, always 

 taking care that the unripened plants are not 

 subjected to bright sunshine during the 

 middle part of the day, for there is still a 

 chance of tender foliage being burn*". 



Where permanent shading in the form of 

 whitewash on the glass is used its removal 

 must take place gradually, thus slowly 

 accustoming the plants to increased light. 

 If possible, the plants should be separated 

 into two lots, one containing those with fully- 



grown bulbs, and the other reserved for the 

 few that require another week or so to finish 

 their growth under shady conditions. 



There are some amateurs who shut the 

 houses up as closely as possible each night in 

 order to save the cost of fuel, which is poor 

 economy indeed. Plenty of air is now needed, 

 and ventilation should always be used when 

 the outside atmosphere is not unduly severe. 

 A little fire heat at night time will cause the 

 air to circulate, as well as maintain a suitable 

 temperature. Shutting up the houses on a 

 summer's afternoon is all very well when a 

 hot steamy atmosphere is required to promote 

 vigorous growth, but during the month of 

 September amateurs would be well advised to 

 discontinue this treatment, or some of the 

 plants may be excited into starting a second 

 growth, which is most undesirable. Modera- 

 tion in all things is now the main point to 

 consider. 



In the cool houses no fire heat will be 

 required until October arrives. The Odonto- 

 glossums are lovers of a cool and moist 

 atmosphere, and a temperature of 50-60 

 degrees will suit them admirably ; no harm 

 will occur if it falls as low as 45 degrees on 

 cold nights, although when this is expected 

 the watering should be done early in the day 

 so that much of it may evaporate before night 

 time. When a cold night arrives unexpectedly 

 the new growths should be examined and any 

 water lodging in them shaken out. This will 

 go a long way to prevent damping off. 



Many Odontoglossums of the crispum 

 section will require repotting, those in the 

 most forward condition of growth being taken 

 in hand first, while the backward plants can 

 wait a few more weeks, and very late ones 

 until the early spring time. The practice of 

 going through a batch of plants and repotting 

 every one, whether they require it or not, is 

 by no means satisfactory even in the large 

 trade establishments, and still less so in 

 amateurs' collections, where a considerable 

 portion of the work is done in odd hours. 



With Odontoglossum hybrids there is a 

 remarkable increase of vigour, making them 

 particularly useful, for they soon overcome 

 any check caused by repotting, while they 



VOL. V. 



35 



