SHADING 21 



all the varieties of Cypripedium insigne, C. Spicerianum, 

 C. Charlesworthii, and all the green-leafed section known 

 as Selenipediums, will thrive admirably, and a very large 

 selection of other showy Orchids, including Zygopetalums ; 

 but again I would say that species which are usually re- 

 garded as warm-house Orchids must be rejected. 



SHADING 



It should be distinctly understood that every Orchid 

 house needs to be fitted with proper means of shading, 

 extending over the whole roof and removable when necessary. 

 Some cultivators think they meet the case by providing 

 shading only on the sunny side, or by painting the glass 

 with some kind of preparation more or less in the nature of 

 whitewash. Such preparations should never be used, be- 

 cause, when this is once placed on the glass, the shade, 

 such as it is, is there in dull as well as bright weather, 

 in the night time as well as the day, and for the greater 

 part of the time, especially in dull seasons, it obstructs 

 light which is necessary for the proper development of the 

 plants. Another important objection to their use is that 

 shading given by these washes wears off and leaves the 

 plants exposed to the full sunlight. The substance is washed 

 off by the rains and carried into the rain-water tanks, thus 

 causing injuries to the plants watered with the polluted 

 water, and rendering unsightly the foliage moistened with it. 



Proper blinds running on iron or wooden supports, raising 

 them well above the glass of the roof, are absolutely neces- 

 sary. Lath roller blinds are excellent for shading, being 

 durable, clean, and easily let down and drawn up. 



