248 THE ORCHID REVIEW. [May, 1913. 
CALENDAR OF OPERATIONS FOR MAY. 
By J. T. Barker, The West Hill Gardens, Hessle, E. Yorks. * 
DurinG the present month Orchids generally will be in growth, and every 
encouragement should be given them to build up and mature themselves as 
quickly as possible. The summer temperatures must now be maintained in 
all departments. When the outside conditions are mild and genial, the 
heat and light from the sun must be husbanded in every possible way that 
is conducive to the welfare of the plants, but during a cold spell allow a 
slight fall in temperature. The following figures are safe and reliable for 
the different departments during the next three months :— 
Cool house: Night, 55° to 60°; day, 60° or as cool as possible. 
Intermediate house: Night, 65° to 70°; day, 70° to 80°. 
Warm houses; Night, 75°; day, 75° to 85°. 
These figures are given as a guide, but local conditions vary, and every 
cultivator must use his own discretion according to circumstances. Undue 
fluctuations of temperature should be avoided. During extremely hot 
weather the thin-leaved Cool-house Orchids are easily injured by excessive 
heat or a dry, parched atmosphere. 
ATMOSPHERIC MOISTURE may now be used most liberally, and with the 
increased amount of ventilation that will be necessary no harm is likely to 
accrue from this source, provided the temperatures are maintained. Avoid 
a hot and dry atmosphere, also a wet and cold one, as both are harmful for 
any length of time. 
VENTILATION.—The ventilation of the houses must have every attention, 
especially in the southern districts where the sun has much power. Air 
should be admitted in every department on all favourable occasions. 
Ventilation during hot and dry weather needs some forethought, as if used 
in excess the humidity of the atmosphere is soon lost, and draughts may be 
easily caused which may do irreparable harm. 
WATERING may be carried on as advised last month right through the 
growing season, but in no case should plants be kept in a saturated 
condition indefinitely, but the compost should be allowed to become dry 
between each application of water to the roots. 
SHADING also must have attention, as the blinds should not be down 
when not required. On the other hand the sun must not be allowed to 
shine on the plants when there is a danger of the foliage suffering. These 
small.matters.are essential’if.the best results are to be attained. 
CATTLEYAS, La#Lias, L&LIOCATTLEYAS, and others of the summet- 
flowering section, which comprise many plants of complex parentage and 
great beauty, are now pushing up their flowers within the sheaths, and it is 
advisable that the plants should be thoroughly cleaned before the flowers 
