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TIBRARY 
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Vol. 4 FIGHT FLORAL CO., Inc. FEBRUARY 
No. 2 22 W. 26th Street, New York 10, N. Y. 1945 
gi stemmed Roses and small-leaved Gardenias. 
Soe , x The better recommendation, despite the scien- 
7s == 2 
BARNEY BONEMEAL 
SHCA 
“A dry creek is an exasperation 
but a flooded one is troublesome.” 
And so itis in a greenhouse. During the Sum- 
mer our humidity in most greenhouses is too 
low, except in localities where normal high 
humidity exists in the atmosphere. Where it is 
low the mere shading of roofs as advocated 
recently at a meeting is not adequate compen- 
sation. True the temperature may be reduced 
somewhat by shading roofs but the humidity 
still remains too low to produce the best 
growth. This is well illustrated by short- 

tific explanation that a 10 deg. raise in tem- 
perature is equivalent to a 30% raise in 
humidity in so far as leaf temperature is con- 
cerned, is to shade the roofs as we recom- 
mended in these pages before and to raise the 
humidity as well. This, of course, applies to 
crops which do better with high humidity and 
obviously not to Carnations or Succulents. 
On the other hand during late Fall and Win- 
ter, the usual sloppiness which exists in many 
greenhouses, due to leaky valves, poor unions 
in pipes and puddles in depressions in walks 
may cause a lot of trouble by producing soft, 
succulent growth with subsequent loppy stems 
and foliage susceptible to all kinds of trouble. 
There needs to be a happy medium, and com- 
mon sense and knowledge of plant habits will 
dictate the procedure. 
Perhaps more specifically, we should provide 
high humidity consistent with fresh air for 
most Orchids (Phalaenopsis being an excep- 
tion). As mentioned before, high humidity is 
desirable for Roses except during the extremely 
dark weather. Gardenias will take it regularly, 
although too high a humidity in December 
may cause bud drop. Hydrangeas will be 
short-stemmed and small-leaved and small- 
flowered if kept too dry during the forcing 
period. Poinsettia leaves and bracts will be 
too small under similar conditions. On the 
other hand, Lilies will stretch too much if 
humidity is too high. Yet in their case if need 
for high temperature arises for quicker forcing, 
it should be accompanied by high humidity. 
Chrysanthemums will produce bigger foliage 
and larger flowers when the humidity is not 
too low, while Geraniums and Carnations do 
better with low humidity. In case of propaga- 
tion very high humidity will give better root- 
ing of Roses, Gardenias, Poinsettias, Chrysan- 
themums, Azaleas, Hydrangeas, provided the 
medium is coarse, well aerated, well drained 
