The Culture of Greenhouse Orchids 



for a night or two uninjured. 0. crispum succumbs 

 at 13°. But this is only a scientific fact, pleasant 

 to recall, when by some mischance the glass shows 

 32° on a winter morning. Assuredly no orchid we 

 cultivate is indifferent to frost. 



During November, December, January, February, 

 and March the night temperature should be 50° 

 to 45°; during April, May, June, July, August, 

 September, and October, 55° ; and always the day 

 temperature should be five degrees higher — 55° 

 and 60°. Of course, this ideal cannot be maintained 

 in summer. Even in a lean-to facing the north, 

 heavily shaded, freely watered and ventilated, the 

 heat will rise to 70° or more daily, nor will it fall 

 much below 60° at night. But under the conditions 

 named — of shade and water and ventilation — not the 

 least harm is done ; neglect of the conditions would 

 be disastrous, however. That must always be re- 

 membered. Upon the whole, too great heat in 

 winter is a much more frequent cause of mischief 

 than summer sun. I repeat that during those most 

 important months — November to April — when the 

 bulk of the plants are setting and maturing their 

 flowers, 55° by day, 50° by night, are the maximum 

 permissible ; and if the glass begin to fall lower in 

 the small hours, so as to touch 45° at daylight, so 

 much the better. 



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