94 PRACTICAL TREE REPAIR 



Nor should any tree receive costly surgical care 

 if it is weak and making little growth. The great 

 army of bark and wood borers and other insect 

 enemies ready at any time to swoop down upon a 

 weakening tree, makes the expectation of life of a 

 weak tree very precarious. Common sense in- 

 dicates that no large sums ought to be risked on 

 sickly trees. 



Again, only after very careful consideration 

 should a hollow tree be filled up which has com- 

 pleted or nearly completed the span of life natural 

 to that species in that climate and soil. Some- 

 times such old trees can be reinvigorated, but in 

 every case the measures calculated to restore youth- 

 ful vigor should be carried out and their success 

 assured, before much filling is done. 



Finally, from the fact that a tree is hollow it 

 does not necessarily follow that a concrete or as- 

 phalt filling is " indicated," as the doctors say. 

 Some decays eat out the entire heartwood and die 

 out with the destruction of the affected wood. In 

 such cases filling is of but little value. The decay 

 has done its work and it is too late to stop it. The 

 drainage of the cavity is usually good, and the 

 inner surface is often so weathered that it is as 

 resistant as a seasoned plank. Such a condition of 

 affairs is often observed in old sycamores. No 

 further treatment is justified than smoothing and 

 painting the walls of the cavity and carefully brae- 



