348 SOME SPECIFIC MODES OF TRAINING 



The leaves serve the important purpose of elaborating the 

 sap of the roots and preparing it for the proper nourish- 

 ment of the tree, and the formation of buds upon the 

 boughs. A tree, therefore, that is deprived of its leaves 

 is in danger of perishing. 



The yearly extensions of wood should be shortened more or 

 less, as the branches approach a vertical line, or the 

 contrary. 



Plants are trained on walls for purposes of 

 decoration or for fruit -bearing. Fruit trees so 

 trained are protected from winter cold, and the 

 fruits receive greater warmth and sunlight than 

 they do when grown free. In sunny countries, 

 with hot weather at the period of fruit -ripening, 

 fruits develop their full color and flavor without 

 the aid of walls. In fact, in America the south 

 face of a wall may be too hot for the best re- 

 sults with some fruits. On a south wall, too, 

 the blossoms open very early in spring and are 

 in danger of being caught by frosts. This is 

 especially true of apricots and peaches, and for 

 them a westerly or even northerly exposure may 

 be preferable. 



In Europe, gardens are very often surrounded 

 with brick walls several feet high ; and in many 

 cases, such walls are built across an area for the 

 particular purpose of fruit-growing. The walls 

 of buildings, whether of brick, stone or wood, 

 may be used. An apricot, peach, pear or other 

 fruit tree trained against a barn, shop, shed or 



