THE GARDENERS' CHRONICLE OF AMERICA. 



359 



CAVITY TREATMENT OF TREES. 



By F. a. r>.\RTi,i--.i r, (."onni-xticut. 



The i-eoplc of tlii.s counlry are lit present giving a 

 great deal of attention to the care and jjreservation of 

 their trees, hut they are still far more concerned in the 

 re]iairing of a tree broken by llic storms, or the filling of 

 cavities formed by wood-destroying fungi than in pre- 

 venting these injuries. Everyljody should bear in mind 

 the fact that it is far more important and effective to 

 prevent these cavities than it is to repair them, after they 

 are formed. Properly filling a cavity will prolong the 

 life of a valuable tree for some time, hut rendering the 

 tree resistant to disease by caring for the small wounds 

 and giving it plenty of proper nourishment will enable 

 the tree to live almost indefinitely. In order to lie able 

 to guard against decay it is necessary to know its cause 



ni:( \vixr, wood siroui.D iik dui;. out 



L\TIL (iOOI) HEALTHY TISSUES 

 .\RE RE.\CHED. 



and how it olitains a Imld upon the tree. The outer Ijark 

 is the tree's natural protection against disease, and if 

 this were never broken it is perhaps safe to say that no 

 cavities could be formed. Unfortunately, however, the 

 bark very frequently is injure<l. The surrounding air 

 is filled with spores of many kinds of wood-destroying 

 fungi. As soon as the surface is exposed the rot fungi 

 gains foothold and in time a cavity is formed, which even 

 with the best care is apt to grow gradually larger and 

 finally the tree is _lost. 



The beginning of cavities is due to numerous causes, 

 the principal ones being wind, lightning, ice-storms and 

 boring insects, or a small branch only may be broken off 

 which receives no attention. Wood-destroying fungi en- 

 ters at the exposed surface and gradual]} weaken the 

 branch until a sudden storm breaks it. .'\ large area is 

 then exposed and the decay continues until the larger 

 branch is broken, and thus the decay mav work it- way 



into the very heart of the tree and finally the whole tree 

 is blown down. The proper treating of the small wounds 

 with a protective dressing might have been the means 

 of saving a \aluable tree, llowever, since people are 

 not aware of the great importance of constantly guard- 

 ing against the entrance of the wood-desti-oying fungi, 

 cavities are formed and once formed should immediatel\- 

 be treated in such a way as to arrest as far as possible 

 further decay. .Mthough decav in trees is comparatively 

 slow we are much more certain to stop entirely the rot 

 in a small cavity than if we wait vmtil it is of consider- 

 able size. 



First, all decaying wood should Ije dug out until good 

 healthy tissues are reached. The shape of the completed 

 cavity should be such that it will naturally hold firmly 

 whatever material is used to fill it. \'ery shallow cavities 

 are not filled at all. Init covered with a good watcrojjroof 

 antiseptic dressing. .\ groove should be cut back of the 

 edge of the bark into the wood a half inch or more. 

 .After the cavit\ is cleaned and correctly shaped, nails 

 should be driven into the inner surface of the cavity to 

 hold the cement. The inner surface should tlien be 



COXCKKI'E ITI.I.I.Nc; IIUILT IN SECTIONS. 



NEW OROWTH WILL SOON FORM 



OVER THE EILLINn. II- THE 



iKi'.i'. IS xiiiokors. 



thoroughh' cauterize<l with some antiseptic matcri.il such 

 as carbolineuim, creosote or tar. .Sometimes in case of 

 water collecting in the base of the cavity copjier sul])hate 

 crystals may be added. The cavity may then be filled. 

 Cement has thus far proveil tu be the most satisfactory- 

 material for filling cavities of any size. It has been found 

 that solid cement will crack with the swaying of trees. 

 This can be overcome liy building in the cement in sec- 

 tions. These sections move slightly one over the other, 

 whereas, in the case of solid cement cracks would be 

 made The filling should be built to conform with the 

 contour of the tree and the edges fliish with the inner 

 bark to provide the best possible conditions for rapid 

 {Continued on pai^e 374.) 



