80 THE ORCHID REVIEW. [May-JuNE, rg19. 
By J. T. BARKER, Orchid grower to His Grace the Duke of 
Marlborough, Blenheim Palace, Woodstock, Oxon. 
CALENDAR OF OPERATIONS FOR MAY - JUNE. 
ay the increased amount of daylight and sun heat, the majority of 
the plants are growing and rooting freely, and every inducement 
should be given them to build up strong, healthy pseudobulbs. The 
temperatures now onwards for the next few months should be raised a few 
degrees in each department, and during bright weather will attain the 
maximum for the year, which is to the benefit of the warmer divisions. 
Cool House Orchids, however, soon suffer from excessive heat, and during 
hot weather must be kept as cool as possible by the use of a greater 
amount of humidity in the atmosphere. In dry districts this; combined 
with the judicious use of the ventilators, is the only means of maintaining 
that cool, buoyant atmosphere which these plants love. , 
ATMOSPHERIC MOISTURE may be used abundantly, as no plants can 
make satisfactory growth in a dry, parched atmosphere, whilst such condi- 
tions bring with them an unlimited increase of insect pests. Unsuitable 
conditions of atmosphere, either too wet or too dry, bring their respective 
troubles, and a proper balance of air, heat and moisture must be maintained 
to secure the best results. Spraying and syringing may be indulged in on 
fine bright days, and only soft tepid water should be used for this purpose. 
On cold, damp days it should not be attempted, and sufficient moisture will 
be obtained by thoroughly damping the floors, stages, &c. 
VENTILATION.—During hot weather the ventilation of the houses will 
need considerable attention, especially the Cool division. This regulates 
the temperature, and combined with a proper amount of humidity in the 
atmosphere, enables the plants to make satisfactory growths, to be ripened 
and consolidated at a later period. The ventilation of the different depart- 
ments must be so arranged that the plants may receive at all times a 
continual supply of fresh air, without causing draughts. The bottom 
ventilators may be left partially or wide open at night, according to circum- 
stances, thereby providing a sweet and healthy atmosphere, without which 
no plant can thrive under the artificial conditions of glass houses. The life 
of the plants depends entirely upon the conditions provided for them, and 
an overheated stuffy atmosphere ‘causes exhaustion. 
WATERING must be done carefully at all times, and the state of each 
individual plant, whether in active growth or otherwise, must be taken into 
consideration. The danger of overwatering is hardly present when the 
compost is full of healthy roots, and the plant is in active growth, but at 
other times an excess of water has the effect of killing the roots. On the 
other hand, an inadequate supply of water is a hindrance to free growth, 
