48 CULTIVATION AND MANAGEMENT 
200 pounds ; muriate or sulphate of potash, 250 pounds ; 
and raw ground bone, 400 pounds. These are the 
amounts for mature trees ; for young trees the amounts 
must be proportionately decreased. When leguminous 
cover crops are grown every year, the nitrate of soda 
may be very greatly reduced or omitted altogether. 
These fertilizers should be applied early in the spring, 
just when growth is commencing. Be careful not to 
overdo the manuring with chemical fertilizers ; an exces- 
sive use of them is apt to burn the humus out of the soil. 
CovER Crops.—Cover crops not only conserve the 
moisture, but they supply humus or decayed vegetable 
matter, a property with which British Columbia orchard 
soils are not too heavily charged as a rule. 
Early in September, or as soon as the fall rains begin to 
come, sow a crop of hairy vetches, red clover, cow peas, 
rape seed, or other pod-bearing plant, and let it stay until 
the following spring, when it should be ploughed in. The 
quantities of seed to sow are—of red clover, 20 pounds to 
the acre ; and of hairy vetches, 50 pounds. It is here 
that the full advantage comes in of sowing a crop of 
clover on the land before the trees are planted at all. 
When they are planted after such a crop, the clover is 
there all ready down below where the roots go, and they 
get the benefit of it from the start. It is not easy to 
realize the immense difference there is between the growth 
of trees so planted and the growth of trees planted with- 
out a crop of this kind. As a rule, it is not advisable to 
pasture these green crops. The crop must be ploughed 
in if it is to serve the purpose for which it was sown. 
Nor must the green crop be allowed to grow too rank and 
