May, 1912.]| THE ORCHID REVIEW. 145 
CALENDAR OF OPERATIONS FOR MAY. 
By J. T. Barker, The West Hill, Hessle, E. Yorks. 
In each department plants will now be making new growth, and every 
encouragement should be given them to build up and mature such growth 
as quickly as possible. To assist in bringing this about, the summer tem- 
peratures should now be strictly adhered to, whenever the outside conditions 
are mild and genial, but should a spell of cold inclement weather prevail a 
few degrees lower will be better than an abnormal amount of fire heat. 
Cool house: Night, 55° to 60°; Day, 60°, or as cool as possible. 
Intermediate houses: Night, 65° to 70°; Day, 70° to 80°. 
Warm houses: Night, 75° ; Day, 75° to 85°. 
The figures are given as a guide, but the cultivator must use a certain 
amount of discretion, according to the outside conditions. 
Cool-house Orchids are soon injured by excessive heat, which many 
found out during the abnormal heat of last summer, and therefore they 
must be kept as cool as possible. 
VENTILATION.—During excessively hot weather the ventilation of the 
Cool-house will need a great deal of attention, as the humidity of the 
atmosphere must be maintained, which is not an easy matter, especially if ~ 
the top ventilators are opened much during the hottest part of the day. 
The temperature of this house should be kept down in the day time by the 
judicious use of the blinds. The top ventilators may be left open during 
the night, when the moisture in the atmosphere will be very beneficial to the 
plants. The ventilation of the other houses must receive some amount of 
forethought and attention, and the great thing to study is to give the plants 
a continual supply of fresh air, without causing draughts. 
ATMOSPHERIC MoISrURE.—With the advancing power of the sun, and 
the warmer weather, more moisture must be maintained in the houses to 
keep the plants in a healthy condition, and as a preventative against insect 
pests. Spraying and syringing may be indulged in frequently on fine 
bright days, but only soft tepid water should be used for this purpose. On 
cold damp days, if done at all, it must be done with great caution. 
WATERING must at all times be done with discretion, as watering a 
plant at the root that does not require it only decays the compost, which 
may in the end destroy the roots of the plant. 
CypRIPEDIUMS.—The potting of the winter-flowering section should be 
brought to a conclusion as soon as possible, as time lost at this season can- 
not be made up. The sooner these plants get established in the new com- 
post the better, as a well established plant produces a larger crop of better 
flowers, than one only half established. 
CaTTrLeyas, La&xias, LeviocaTTLeyas, and others of this family that 
