48 THE ORCHID REVIEW. — [Marcu-Aprit, 1919. 
| CALENDAR OF OPERATIONS FOR MARCH-APRIL. | 
By J. T. BARKER, Orchid grower to His Grace the Duke of 
Marlborough, Blenheim Palace, Woodstock, Oxon. 
\ Vila the gradually lengthening days comes the necessity for an 
; increase of temperatures in the Orchid houses; and this is perhaps 
the most difficult season of the year to maintain regular conditions, 
and the proper balance of heat and moisture so essential to success. 
Owing to the many sudden changes which occur -during this fickle 
period, the grower should be constantly on the alert, and prepared for 
whatever fluctuations may occur. A very cold morning may be followed by 
bright sunshine accompanied by a cold east or north-east wind, and there- 
fore a close watch is necessary on the heating apparatus to prevent undue 
fluctuations. During periods of trying times like these it is often impossi- 
ble to admit air to counterbalance the heat from the pipes and the sun, 
hence the necessity of using abundance of moisture to prevent a hot, stuffy 
atmosphere, which is not only harmful to the plants, but one which insect 
pests revel in, and these, if not checked, will soon do irreparable harm.. 
TEMPERATURES.—We may now look for more genial conditions, which 
will help the plants to start on their annual growth. A slight increase in 
the temperatures of the houses is now permissible, with a corresponding 
increase in atmospheric moisture, according to the different houses and the 
plants grown in them. These increases should be gradually advanced until 
the summer or growing conditions are reached. 
VENTILATION.—All Orchids delight in a sweet and pure atmosphere, 
hence the necessity of paying careful attention to the manipulation of the 
ventilators, so that no draughts are caused, as no plant can resist draughts, 
any more than a human being can. Tender plants are like delicate children, 
and should be studied in much the same way as regards their requirements, 
and it is useless to expect them to thrive if placed under adverse conditions. 
WATERING.—The plants, now they have commenced their growth, will 
gradually take up more water at the roots, but care is still necessary in its 
application. Some plants will be more advanced than others, therefore will 
require more to support them; but for some little time, until the plants get 
fully into growth, allow them to dry out between each application of water. 
Make sure that the plant actually requires water before it is applied, and 
Special care must be taken with those that have been recently repotted. 
SHADING.—Up to the time of writing there has been no necessity to use 
shading ; but when the wet, dull weather, which we have been having for 
some considerable time, passes away, we may experience some bright, sunny 
days, hence the reason why the blinds should be in position ready for use. 
After weather and conditions like those we are passing through, the plants 
