THE PROGRESS OF ORCHID CULTURE IN AMERICA. 147 



English orchid houses are especially constructed with flues 

 opening upon the hot water pipes, which distribute constantlj- a 

 supply of fresh air without creating injurious cold drafts ;and such 

 a plan is without question a very excellent one. From the first of 

 December to the middle of February, in this latitude, all shading 

 should be removed from orchid houses, and the full benefit of 

 ever}' ray of sunlight secured. A few species like the Phalsenopsids, 

 Bolleas, Pescatoreas, some of the Cypripediums, and some other 

 scattering examples are benefited by slight shading in winter, on 

 very bright days, but the number is less than might be imagined ; 

 and even Plialvenopsis Schilleriana enjoys the winter sunshine with- 

 out injury. Full exposure to all the sunlight which may be had in 

 winter is of great benefit to orchids ; it ripens the bulbs, solidifies 

 the growth, and stimulates the flowering qualities ; and stronger 

 growth and better root action result in the spring. So important 

 is this, that the glass should be clean and free from everything 

 which might serve to obstruct the sun's rays. In many collections 

 you will find the opposite state of things, but a close observation of 

 most of the larger and best grown collections of the country justi- 

 fies the conclusions I have stated. 



From the middle of February, or the first of March, to the first 

 or middle of INovember, according to the incline of the house, 

 roller shades of the thinnest cheese cloth, running on slats 

 elevated six inches from the glass, are better than whitening 

 the glass, as they serve to keep the houses much cooler than if the 

 sun's rays strike directly upon the glass. For a large number of 

 houses shading of this kind m'av not be possible, but it is by far 

 the best method yet devised ; the great advantages being that on 

 cloudy days the shades can be raised and the benefit of the eai'ly 

 morning and late afternoon sunlight can be secured without in- 

 jury, and above all, in this hot climate, a cooler and more moist 

 condition of the atmosphere can be maintained in the houses. 



Orchids which are not kept clean cannot be health}', and what 

 with white and brown scale, black and yellow thrip, and green fl}', 

 the cultivator needs to be alert. I believe in mild fumigation once 

 a week, as the only proper method for keeping a house clear of 

 thrip and green fly, tiiough many growers have an impression 

 that orchids do not like tobacco smoke. I have never known one, 

 even of the thin-leafed kind, to be injured by a light fumigation 

 properly given ; and two of these in succession, or one given ever\^ 



