PRUNING OP FOREST TREES. 91 



to take its place. A branch too much inclined 

 from a proper direction may be drawn up by 

 tying to other branches, just as the whole tree in 

 a young orchard, is often corrected from a leaning 

 tendency by tying to stakes. If a cord is not at 

 hand the forester sometimes uses a small branch 

 still attached to the tree as a wythe for tying up a 

 leaning top or irregular branch until it will keep 

 in place without help. These methods are shown 

 in the annexed engravings.^ 



These attentions to details, always important, are too generally neg- 

 lected, and may be not practicable with us in the case of forests ; but 

 sometimes a little reasonable care will, if timely bestowed, prevent a 

 valuable tree from becoming good for nothing. 



After trimming the lower branches of a tree, it will be often found 

 that shoots will start out from the edges of the wound, or in other 

 places, which will sometimes, if allowed to remain, take inordinate 

 growth. If not desired, they should be removed by preference the sec- 

 ond or third year in August or September, after the wood of the year 

 has been formed.^ For this purpose various instruments have been de- 



' A careful attention to the condition of an old tree is not less useful than in the 

 young, the (hief anxiety in this case, being to remove dead or dying branches or 

 rotting parts with as little injury as possible, and to protect the wood until it can 

 heal, or if this be hopeless, to exclude air and moisture, and thus proveat or retard 

 further decay. Where a section is too large to admit the hope that it will ever grow 

 over, the life of a tree may be sometimes prolonged by covering the exposed wood with 

 a disk of lead, zinc, or tin, carefully secured around the edges, so as to exclude the air 

 and moisture. In some cases aged trees in parks and private grounds, which are val- 

 ued on account of historical or family associations, may thus he preserved, and their 

 vigor in some degree renewed. 



Whenever a piece of bark has been removed down to the sap-wood, the adhesion 

 oannot be restored, however carefully replaced, and the part exposed loses its vital- 

 ity, and if left unprotected, tends sooner or later to decay. The living parts adjacent 

 will begin to form new wood, and if the injury be not extensive, they will eventually 

 close over the wound, and in course of time leave no external trace. But if large, the 

 exposed wood tends to decay, and before it has had time to close, a rotten cavity is 

 formed, extending somewhat upward, but chieiJy downward in the direction of the 

 vessels of the wood, and sometimes quite into the root. 



Although no application, however soon applied, will supply the place of the natural 

 covering, a coat of coal-tar or other paint would afford great protection, and often 

 prevent the rotten cavity from forming, until the wood had united over the injured part. 



Whenever the bark is loosened, the wood dies under the affected part, the same as 

 though it had been wholly removed, and it is not unfrequently found in orchards and 

 plantations that this loosening of bark has existed for some time without notice, causing 

 a languishing appearance without visible cause. The healing process by overgrowth 

 goes on in such cases as when fully exposed, and the treatment needed is the re- 

 moval of the dead bark and protection as in case of other wounds. 



Such exposed places and rotten cavities are further injurious by harboring insects, 

 and especially those whose larvae feed upon decaying wood, and through whose agency 

 the destroying process is hastened. The remedy, so far as known, consists iu cleaning 

 out the decayed part as fully as possible, applying coal-tar, or other covering, freely to 

 the surface, and, where it is possible, plugging up the orifice with hard wooden wedges 

 or pins, which should be cut close, and be allowed to grow over. Sucii cavities, if too 

 large for this treatment, may, in old trees, be sometimes hindered from growing larger, 

 by closing them with carefully fitted planks or metal sheets, so as to exclude the air. 

 The borers that infest dead wood might not respect a plank or board which has al- 

 ready lost its vitality, but a sheet of zinc or other metal would afford complete immu- 

 nity from their attack. 



2 The side branches that spring out where an oak forest is thinned, and the trunks 

 exposed to light, would, if allowed to grow, interrupt the balance of growth, and cause 

 the top to die out. The rule laid down by Lorentz and Parade is, that the pruning of 

 this side-growth should commonly begin three years after the thinning, and be re- 

 peated every three years to about half or two-thirds the period of revolution. By this 

 time the younger growth will have come up high enough to hinder further trouble 

 from these branches along the trunk. — Culture des Bois, 2d ed., p. 299. 



