THE TREATMENT OE THE SHOOT 137 



A cut is least dangerous when inflicted upon a leafy shoot, 

 first of all, because, owing to the transpiration of the leaves, 

 the shoot will not contain sufficient water to cause an accumu- 

 lation of it on the cut surface ; and secondly, because the leaves 

 will at once supply sufficient food material for the healing of 

 the wound. If ripened wood has to be cut, the early autumn 

 or late winter should be selected for the purpose. Early in 

 the autumn the branches have still sufficient activity to form 

 the closing layers, and thus to protect the shoots from the wet 

 of the autumn and the cold of the winter. If the pruning 

 takes place late in the winter, no injury from frost need be 

 feared for the ripened wood, and as the tree will soon enter 

 upon new activity, the healing of the wound will take place 

 at an early period. 



Great care must be taken in the pruning of trees bearing 

 stone-fruits (cherries, plums, &c.), and in the South also in the 

 case of orange-trees ; in fact, in all cases where the plants are 

 liable to the exudation of gum. If the cuts are inflicted at 

 a time when a considerable formation of new tissues is going 

 on, gum is sure to flow sooner or later from near the cut. A 

 very easy way of demonstrating this fact is to make every 

 month during the winter an incision into a cherry or plum- 

 tree, reaching down to the wood. It will be found in the 

 summer that, from all incisions which were made in spring, 

 gum will be exuding. If one is forced in the case of other 

 trees to prune during the bleeding season, cloudy and cool 

 days should be chosen, as the pressure of the sap is least 

 on such days. Prune as early as possible trees producing 

 strong shoots, which, as a rule, are rich in water, and therefore 

 would suffer most from an excessive loss of sap. The conse- 

 quences of such a loss would be a retarded period of flowering, 

 irregular ripening of fruits, and an insufficient ripening of the 

 wood. 



§ 27. How does summer-pruning differ in its effects from 

 winter-pruning ? 



If the term winter-pruning is given to any removal of 

 shoots during the resting period of a woody plant, we may say 



