PRVNISG. 299 



of pots, previously to laying on the drainage ; a basket of live moss, a 

 box of soot, and one of rotten cow- dung. 



Growing hardy plants in pots, and especially the more rare kinds of 

 trees and shrubs, for the purpose of transport, is one of the most useful 

 purposes to which the practice of potting can be applied. Great care 

 must, however, be taken not to keep the plants so long in the pots as 

 to cause the roots to become matted. 



Pruning. 



Pruning consists in depriving a plant of a portion of its stem, 

 branches, buds, leaves, bark, or roots, in order to produce particular 

 effects on the part of the plant which remains. There are different 

 kiuds of pruning, named after the manner, extent, and implement used, 

 such as knife-pruning, lopping, clipping, disbudding, disleafing, dis- 

 barking. pinching, &c. The instruments necessary for these operations 

 are chiefly the pruning-knife, the bill, the saw, the cutting-shears, and 

 the clipping-shears; but there are some other instruments, such as the 

 pruning-chisel, the averruncator, the girdling-machine, &c., which are 

 occasionally used. 



The specific principles on which pruning is founded, and its general 

 effects, are these : The nutriment of plants is absorbed from the soil 

 by their roots, and formed into branches, flowers, and fruit, by their 

 buds and leaves. If the stem and branches of a plant contain a hundred 

 buds, by removing half of these the shoots or fruits produced by the 

 remainder will be supplied with double their former supply of nourish- 

 ment ; and if all the buds be removed but one, that one may be able 

 to monopolize the major portion of the sap that has been distributed 

 into a hundred channels, consequently the one bud must be developed 

 into a very strong shoot. One of the specific principles of pruning is 

 the stimulus given to vitality. When the leading branch of a small 

 tree, which, perhaps, has not been growing well, but has got the roots 

 fully established, is cut back to one bud, not only is the flow of sap 

 which should have supplied all of the buds diverted into this one, and 

 the shoot made thus more vigorous, but the vitality of the tree has 

 acquired an impetus that it did not formerly possess. From a lazy 

 slow-growing plant it has been converted into one of a quick, healthy, 

 vigorous growth, a stimulus is given to the roots also to increase, and 

 the tree is entirely renovated. The benefit is lasting, not temporary, 

 and will continue, if circumstances are favourable, and no check of 

 bad soil or bad weather ensues to counteract its vigour. It is thus 

 that the forester cuts back his oak plants in the forest, after being a 

 few years planted, and trains a single shoot from the bottom, knowing 

 well that the vigour of this one shoot will be lasting ; that the impetus 

 given to the growth of the tree will continue ; and that, in a few years, 

 the cut-over tree will be many times larger than those allowed to stand 

 uncut. It is thus that nurserymen increase the vigour of their young 

 plants by pruning ; and that gardeners, when pruning for wood, cut 

 farther back than when pruning for fruit. On the other hand, when the 



