CHAP. 40.—METHODS OF IRRIGATION.
Watering is good for trees during the heats of summer, but
injurious in winter; the effects of it are of a varied nature in
autumn, and depend upon the peculiar nature of the soil.
Thus, in Spain for instance, the vintager gathers the grapes
while the ground beneath is under water; on the other hand,
in most parts of the world, it is absolutely necessary to carry
off the autumn rains by draining. It is about the rising of the
Dog-star that irrigation is so particularly beneficial; but even
then it ought not to be in excess, as the roots are apt to become
inebriated, and to receive injury therefrom. Care should be
taken, too, to proportion it to the age of the tree, young trees
being not so thirsty as older ones; those too which require the
most water, are the ones that have been the most used to it.
On the other hand, plants which grow in a dry soil, require no
more moisture than is absolutely necessary to their existence.