JANUARY, 1907.] THE ORCHID REVIEW. 9 
CALENDAR OF OPERATIONS FOR JANUARY. 
By W. P. Bounp, Gatton Park, Reigate. 
ATMOSPHERE.—To maintain Orchids in a healthy state during the short 
dull days of winter, it is essential that all the houses should be well charged 
with pure air daily, and to bring this about it is necessary to have a good 
system of bottom ventilation, so that the air admitted can pass over the hot 
water pipes before coming in contact with the plants. The Cool or 
Odontoglossum house is generally well looked after in this respect, but it is 
equally necessary for the well-being of the plants in the warmer houses to 
have a sweet atmosphere at alltimes. I prefer to fire more rather than not 
admit any fresh air. There are not many days in the yeaf when it is not 
possible to have the bottom ventilators open, if only for an hour or two, but 
generally speaking they should only be closed entirely during very severe 
weather, or when the wind is blowing from the north or east, and then 
sufficient fresh air finds its way into most structures. 
TEMPERATURES.—In addition to a sweet atmosphere, it is also well for 
the inmates of the houses to keep quiet temperatures, but to lay down any 
hard and fast rules as to what this or that house should be in the evening 
or morning is misleading, for what is correct one day is quite wrong the 
next, and the external conditions must be observed hour by hour and day 
by day. During weather when the outside temperature falls as low as say 
20°, the morning temperature of the Stove Orchid house should be 60°, 
Cattleya House, 58°; Intermediate House, 56°, and Odontoglossum House, 
48°. Now take the temperature outside at 40°, and then the Stove should 
be 64°, Cattleya, 60°; Intermediate, 58°, and Odontoglossum, 52°, the first 
thing in the morning. A slight guide can be taken from these figures, 
bearing in mind that when we have severe weather, and a low temperature 
has to be maintained, the houses and plants should be kept in a com- 
paratively dry state. Plants will not suffer from low temperatures if they 
are sufficiently dry. Another important point is that the lowest tempera- 
ture in the houses during the twenty-four hours should be the first thing in 
the morning, with a gradual rise till mid-day, and then a gradual fall till 
the next morning. At this time of year a rise, without the aid of sun heat, 
of about 5° between the morning and mid-day temperatures will be ample, 
but with the influence of sun heat more will be beneficial. A great aid 
_ towards making a genial temperature during severe weather is to lower 
the blinds and cover up the ends and sides of exposed houses each evening, 
and when this is done it will be found that it requires much less fire heat 
to maintain the same temperature. There are few things that Orchids 
resent more than over-heated pipes. 
SPATHOGLOTTIS.—In the stove these most desirable and nearly 
