IMPORTANCE OF AIR DRAINAGE 3 
formation of the surrounding country, a free circulation 
of the air will at all times prevail naturally. Air drainage 
is as essential to the foliage of fruit-trees as soil drainage 
is to their roots. 
The point I am endeavouring to elucidate may be 
crystallized in the two following pieces of advice : (1) Don’t 
make an orchard on the bottom of a valley or on a dead 
flat, and this last applies to a dead flat on a bench or 
other high ground equally as to a flat in the bottom of 
a valley. (2) Choose for your orchard land that lies on 
a gentle slope. The slope must not be too steep. Not that 
trees will not grow on a steep slope ; for they will, and do. 
But it is then not so easy to get at them to prune them, 
spray them, cultivate them, and gather the fruit. The 
objection to a slope which is too steep is that, when the 
snows begin to melt in the spring, the water tends to 
wash or leach off the rich surface soil; and this danger 
becomes accentuated after the wild surface vegetation 
has been removed by clearing and cultivation. Again, 
if the slope is too steep, you will find it difficult—maybe 
altogether impracticable—to give that amount of cultiva- 
tion to your fruit-trees which they require, unless, indeed, 
your orchard is so small that you are able to do all your 
cultivation by hand labour. Even a gentle slope, pro- 
vided the surrounding geographical features are not 
altogether adverse, will generally of itself secure you an 
efficient air drainage, and thus give you one of the essential 
conditions of an ideal orchard site. On the other hand, 
in Colorado the safest situation for an orchard is often 
the entrance to the deep cafions, up and down which, 
day and night, breezes blow with great regularity ; and 
