348 



PRUNING. 



of what would otherwise be mere alburnum, becomes similar to the heart 

 wood ; and this may be one reason why the boards made from such trees 



are found not 

 to warp. Be- 

 fore I girdled, 

 I never could 

 have a ladder 

 made of larch 

 that would 

 continue 

 straight for a 

 month ; but 

 now I have 

 them made 

 durably per- 

 fect. Gard. 



Fig. 262. Perspective view of the girdling machine. ,.-. .. ^^.Q 



779. The seasons for pruning vary according to the object in view. Where 

 wood is to be cut out or buds removed, so as to throw strength into the 

 remaining parts of the tree, the sooner the operation is performed after the 

 fall of the leaf the better ; because as the sap is more or less in motion, and 

 consequently impelled to all the buds throughout the whole of the winter, 

 that which would have been employed on the shoots and buds cut off is 

 saved, and those which remain are invigorated by it. Next to autumn, 

 winter is to be preferred for the same reason ; but in this season mild 

 weather should always be chosen, because the frost, if severe, will seize on 

 the moisture of newly-made wounds, and rupture their surface. In pruning 

 forest-trees, large branches should never be cut off in autumn, because as 

 they cannot heal over till the following summer, decay will commence on 

 the surface of the wound. Spring, just before the rising of the sap, is a better 

 season ; but better still, a fortnight before midsummer, at which period the 

 returning sap will commence to deposit a coat of alburnum on the lips of the 

 wound. The worst season in which any description of wood-pruning can be per- 

 formed is the spring just before the expansion of the leaves, when the sap is 

 rising with the greatest vigour. The slightest wound made in many plants both 

 ligneous and herbaceous at this season, especially young vigorous ones where 

 the sap-vessels are large, occasions a great loss of sap, which must necessarily 

 weaken the plant, unless speedily cheeked by the only effectual mode in 

 which this can be done, the expansion of the leaves. For disbudding and 

 ringing, spring is the most suitable season, at least for the latter practice, 

 because, as we have before observed, nothing is gained by ringing before the 

 leaves begin to expand. Buds which are to be removed should remain as 

 short a time after they are formed by the leaves as possible ; but as the 

 labour is much greater in taking them off in autumn and winter when they 

 are small, than in spring when all their parts are more or less expanded, 

 the operation is generally deferred till the latter season. For disleafing, 

 it is necessary to commence as soon as the leaves begin to expand, and 

 continue it as long as they are produced. The advantages of pruning just 

 before midsummer are, that the wounds may be partially healed over the 

 same season, and that the sap which would have been employed in maturing 

 the shoots cut off is thrown into those which remain. The disadvantages 



