1 66 PRACTICAL TREE REPAIR 



must be filled up with asphalt or a heavy mixture 

 ofi ashes and tar. The next step depends upon 

 the nature of the bottom of the excavation, espe- 

 cially as regards the number of exposed roots. 

 If the soil has been dug out from beneath the 

 crow;! of the roots, it is usually better to replace 

 it with packed ashes or gravel before beginning 

 the concrete filling. The reason for this is that 

 these materials do not pinch growing roots, as 

 concrete does, and yet they are effective guards 

 against insects. In front, however, the concrete 

 ought to be carried fairly deep into the ground, 

 especially if there is any idea that the filling will 

 serve as a strengthening buttress to the tree. 



The concrete filling should next be put in. 

 Though it may seem that the tree can sway but 

 little so near the ground, it is usually advisable 

 to divide even a low basal filling into sections, in 

 order to anticipate and control the formation of 

 cracks. The first division may be two feet, more 

 or less, from the ground, according as the tree is 

 large or small. 



Concrete fillings of basal cavities can often be 

 left without any surface dressing. As a rule, 

 however, it is safer to paint them, after they have 

 hardened, with tar or asphalt, giving particular 

 attention to the edges. 



In cases where the decay, starting at the base 

 of a tree, has worked upward in the trunk, the 



