PRUNING. 



255 



all trees, whether large or small, the powerful 

 acid it contains renders it unsafe to smear over 

 young bark. It should not, therefore, be ap- 

 plied so abundantly or carelessly to wounds 

 that it runs down on to the healthy surface of 

 other branches. 



The pruning of dry-wooded trees like Oak, 

 Elm, Ash, Beech, &c, may be safely done at 

 any season of the year 

 that is most conve- 

 nient, but the removal 

 of large limbs is, on 

 the whole, better done 

 in autumn or early 

 winter. This allows 

 the surface of the 

 wound to harden and 

 the tar to get thor- 

 oughly set before the 

 strong flow of sap be- 

 gins again in spring. 

 This rule should be 



particularly adhered to in the case of the resin- 

 bearing conifers, which have been known to 

 bleed to death through pruning in spring. Fig. 

 329 shows a large wound partly healed under 

 proper treatment. 



Fig. 329.— A Healing Wound. 



Fig. 330.— Old Oak pruned. 



The chief cause of poor health in old trees is 

 insufficient nourishment. This may arise partly 

 from the decay which has been allowed to set 

 in upon the trunk and branches, but it is more 

 often directly due to impaired root-action. The 

 balance between the leaf-bearing surface and 



Pruning of Old or Sickly Trees. — One of the 

 advantages to be derived from pruning, to 

 which allusion was made at the commencement 

 of this chapter, was that of improving the 

 health and renewing the vitality of old trees. 

 A very common object in gardens and parks 

 is an old tree, valued perhaps for its age, its 

 history, or its rarity, with its trunk and 

 branches decayed here and there into cavities 

 or studded with dead snags, and even its 

 healthiest branches straggling, gaunt, and ill- 

 furnished with foliage. It is such trees that 

 pruning will often invigorate and improve. 

 The first step in their treatment would be to 

 prune off all the snags close to the trunk, in 

 accordance with the methods already described. 

 The next would be to clean out the cavities of 

 all decayed wood and accumulated filth, to give 

 the surface of the wood inside a liberal coating 

 of tar, and then to plug them up with neatly 

 fitting pieces of oak or other lasting wood, the 

 ends of which must be left even with the trunk 

 and tarred over. If the tree is not too decrepit, 

 new wood will gradually close over this " stop- 

 ping" as if it were an ordinary wound (see 

 fig. 329). The living, more or less healthy 

 head of the tree now remains to be dealt with. 



fill" • <~* 

 Fig. 331.— Old Oak restored. 



the roots has by some means been destroyed. 

 Pruning can in a great measure restore this. 

 By a careful shortening back of the branches 

 and a general reduction of the head of the tree 

 (it may be by as much as one -half and still 

 allow the natural outline of the tree to be 



