S2 Principles and Practice of Pruning. 



ment afforded by the leaves. The only exception is the temporary 

 supply furnished by the cells in the body of the tree. New roots 

 are commenced before the leaves expand, as may be seen on young 

 seedlings, the roots of which have been trimmed, and where the 

 new white fibres protrude just as the buds are swelling. The same 

 occurs on the roots of trees transplanted in autumn, after the leaves 

 have fallen ; but this effect is only temporary, continued growth 

 requiring that both leaves and roots should work together. On the 

 other hand, the nutriment laid up in the cells will sometimes supply 

 the leaves for a short period, provided care is taken to furnish the 

 requisite moisture at their surfaces by means of a bell-glass to retain 

 a damp atmosphere. Cuttings are often thus started, a small por- 

 tion of leaves being allowed to remain upon them to assist in the 

 emission of new roots. But, if the leaves are placed in a dry air, 

 they soon pump out and carry off the moisture, and the shoot, leaves 

 and all, withers in a short time. If all the leaves had been cut off, the 

 shoot would remain plump much longer a fact well known to nur- 

 serymen and others who preserve scions for budding. 



Proper Time for Pruning. Many cultivators have been misled 

 into the opinion that early summer is the best time to prune, from 

 the fact that the wounds heal more readily. Priming after the tree 

 has commenced growth has a tendency in nearly every instance to 

 check its vigor. For this reason, where the rapid formation of 

 young wood is desired, the work must be performed before the buds 

 begin to swell. Some planters have objected to shortening-in the 

 shoots of newly-set trees, because by doing the work too late, or 

 after the leaves were partially or wholly expanded, they have injured 

 and not benefited them. Any one may easily satisfy himself on 

 this point by pruning-back the heads of a dozen trees early in the 

 season, and leaving those of another dozen until the leaves have 

 opened. They will present the appearance represented in the fol- 

 lowing figures, before the close of summer the first (Fig. 97), with 

 strong, thrifty shoots ; the latter (Fig. 98), with short, stunted growth. 



There may be an exception to this general rule, where a slight 

 amount of pruning in summer, not sufficient to produce any mate- 

 rial check in growth, may be useful in improving the shape of the 

 tree ; such, for example, as the removal of an occasional unneces- 

 sary shoot or one-sided branch. 



As fresh wounds always render trees more liable to be affected by 

 intense cold, quite hardy trees only may be pruned any time during 

 winter. On those inclining to be tender the operation should be 

 deferred till towards spring. 



