PRUNING OF OLD TREES 



157 



be necessary as the tree gets older. Occasionally large limbs 

 must be cut off for various causes. When this operation is 

 made necessary, care must be taken to make clean, smooth 

 cuts. The wounded part should be covered with some 



Fig. 71. — An injured tree repaired with cement. 



material like white lead paint to protect the open cut. Occa- 

 sionally grafting wax is used, but this material is expensive 

 and not very satisfactory. Other materials have often been 

 recommended, but the safest course to follow is to apply those 



