216 AJiTNUAL REPORT 



The condensing qualities of clover are similar, but not equal to 

 those of buckwheat. The experience of the most successful fruit 

 growers proves that it is absolutely necessary that the ground in 

 orchards should be shaded by something during the growing sea- 

 sons. Therefore they should never be used as pastures, as the 

 eating of the grass or clover by animals would expose the surface 

 of the ground to the sun. Clover should follow buckwheat as an 

 orchard crop, but where it cannot be successfully grown, other 

 hardy kinds of grass may be used instead of it. Neither buck- 

 wheat, clover, nor grass should be removed from orchards. When 

 such crops shall become sufficiently matured, they should be cut 

 and allowed to remain on the ground as a mulch. Bearing 

 orchards which have been seeded to grass should have a liberal top- 

 dressing of well-rotted manure every three or four years. In many 

 places fruit growers resort to pruning at certain seasons of the 

 year to reduee the vitality of trees and render them fruitful. In 

 moist climates like that of England, trees require pruning for the 

 purpose of letting light and air into their tops. But it is unsafe 

 to reduce the vitality of trees on account of the severity of our 

 winters, and the remarkable dryness of our climate renders it 

 unnecessary to make their tops more open. In fact, our trees 

 require no pruning, except to give them the required shape and 

 keep them in proper shape afterwards. When it shall become 

 necessary to prune, the operation should be performed immediately 

 after the buds have opened into leaf in the spring. If the work 

 should be done then, the wounds will be more likely to heal 

 before winter than wounds made later. In places where the 

 atmosphere is more moist, large limbs may be removed from trees 

 in June, or later, without danger of injury, but by exposing the 

 bare wood of trees to the winds during winter in Minnesota would 

 invariably cause them to become "black-hearted." Our fruit trees 

 have been seriously injured very frequently by a cause which has 

 received but little attention. In bearing orchards nearly all of the 

 trees lean more or less to the northeast, and the bodies of those 

 which lean most are generally badly scabbed or rotten on their 

 southwest sides. About the tenth day of April, 1880, I examined 

 the different varieties of trees in my orchard and nursery 

 carefully, and found them in a healthy condition. Four days 

 later, when they were full of liquid sap and their buds 

 were beginning to open, the mercury stood for hours at 

 from 85'' to 90° in the sun. In about a week afterwards 

 I examined my orchard and nursery trees again, and found the 



