152 VEGETABLE FORCING 
sunshine,it may be unnecessary to water oftener than once 
a week, or even at longer intervals under certain condi- 
tions. On the other hand, in the summer it is usually 
necessary to water every day and sometimes twice daily. 
Whether it is summer or winter, much less water is re- 
quired on cloudy days. 
It is always better to water when the temperature of 
the greenhouse is rising rather than falling. Unless the 
water is applied in a fine spray, it will make the soil 
cooler, which, of course, is undesirable, but there need be 
no anxiety about this matter if the temperature of the 
houses, due to the rays of the sun or the heat from the 
boiler, is gradually rising. Then, too, in order to prevent 
injuries from various fungous diseases, the foliage of the 
plants should be dry or free from excessive moisture 
during the night. For the two reasons just given it is 
preferable to water the beds in the forenoon, and that is 
the general practice among greenhouse growers of vege- 
tables and flowers. 
The pollination factor should also have consideration. 
Pollination is most active when neither the atmosphere 
of the house nor the plants themselves contain much 
moisture. This matter should be watched closely in 
tomato and cucumber houses, especially when there is 
dull, cloudy weather. Under such conditions an abun- 
dance of water should be used each time so that it will be 
unnecessary to water more frequently than is absolutely 
required. If the fruits are not setting well, it will be an 
advantage sometimes to use less water than is actually 
needed for the plants, in order to maintain lower 
humidity, which is favorable to the pollination of the 
flowers. 
If additional humidity is needed for any purpose, and 
the beds should not be watered, the walks may be wet 
down several times a day, if necessary. 
It will be seen from the foregoing remarks that no 
