require watering once a week others 
will want attention every day, so much 
depends on root activity and the kind 
of compost used. Only sufficient water 
should be given to prevent the pseudo- 
bulbs from shrivelling, any excess is 
likely to cause the plants to commence 
a new growth at a most unfavorable 
time of the year. 
Temperature. 
As regards temperature, a number 
of the Orchids in nature grow at a 
high altitude and while during the 
day they are subject to the direct 
heat of the sun during the summer 
solstice, yet it is not unusual during 
the winter solstice during the colder 
periods to find some of them covered 
with hoarfrost. The respective degrees 
of warmth found most conducive to 
the health of the plants are as follows: 
Cattleya House: 
Summer—60°-65° night 
65°-70° day 
Winter——55°-60° night 
60°-65° day 
These temperatures may be raised 10°- 
15° by solar heat. 
Cool House. 
The temperature should be kept as 
near 60° as possible by day and 55° 
by night during summer. 
In winter the night temperature 
may fall to 45°-50° without injury to 
the plants, but should be increased 
several degrees by day. 
Ventilation. 
Plants should receive the optimum 
amount of heat and light from the 
sun at all times, compatible to their 
safety during the several months of 
the year. Air in the greenhouses bot- 
tled up becomes superheated, and the 
plants will not thrive in a stuffy at- 
mosphere. On all days during mild 
weather air should be administered 
from the top ventilators. During the 
early spring, fall and winter months 
the top and bottom ventilators should 
not be opened at the same time, as 
this is likely to create a draught which 
is very injurious to the plants. 
Plants recently potted should re- 
ceive a little more shade than those 
fully established. A plant that is well 
established quickly replaces the mois- 
tureture that is transpired from the 
leaves and light and air on the plant 
acting as an incentive to root action, 
as more call is made on the roots for 
moisture. 
Repotting for a time afterwards dis- 
organizes the balance between the foli- 
age and roots. The roots being unable 
for a time to normally function. 
At this period therefore, instead of 
giving the plant the light and air 
which it would in a normal condition 
enjoy, less air and more shade will be 
necessary for a time and to check 
transpiration the plant should be more 
frequently sprayed and great care must 
be exercised when watering at the 
root until the re-establishing period is 
over. 
Insect Pests. 
Thrips are one of the arch enemies 
of Orchids; the damage by these in- 
sects is often done before their pres- 
ence is detected. Systematic spraying 
with an insecticide is the safest and 
surest means to keep the plants clean 
and healthy. Occasional fumigations 
are necessary if the plants are badly 
infested. Avoid heavy fumigations. 
Give light fumigations more frequently 
if thrips are noticed on the plants. 
The plants do not like fumigations 
and should not be subjected to them 
only of necessity. Plants should not 
be subjected to fumigation more often 
than once a month. 
