PLANTING AND CARE OF TREES 139 



and ma}^ be taken from the same tree or some other tree of the same 

 species. The scions shoiikl have their leaves removed, their ends 

 cut wedge-shaped, and slioidd be just long enough to extend under 

 the bark about an inch at each end. The whole wound, scions and 

 all, should be covered with soft grafting wax and cloth bandages. 

 The scions, when they become united to the bark at both ends, serve 

 to conduct the elaborated food material down to the lower part of 

 the tree. In time the wound will heal over completely. (See fig. 

 62). 



Wounds of the previous season, or those that have been allowed 

 to dry out, will require different treatment. A girdled tree, if not 

 treated soon after the accident, will die, but so long as there is a 

 strip of bark remaining there is hope for the tree. In such cases, 

 the edges of the wound should be cut back to living cambium and 

 the wound thoroughly sterilized with copper sulphate, one pound 

 to ten gallons of water. The whole wound, as soon as dry enough, 

 should be painted with ordinary white lead paint, or with coal tar, 

 and then covered with zinc. The zinc should be cut so that it will 

 fit exactly inside of the wound, and in this way allow the bark or 

 margin of the wound to heal over the edge of the zinc. The edge 

 of the zinc should be firmly nailed down, using large-headed nails 

 not more than an inch apart. The zinc may be painted any color 

 that will be inconspicuous. If the zinc should become broken so 

 that water may enter, it should be promptly removed and replaced 

 with whole strips. 



Filling Cavities — Many trees whose trunks have been complete- 

 ly hollowed out, have been saved from breaking down by the use 

 of gement filling. Cement is used largely for support and acts 

 as a reinforcement. In order that there should be no further 

 decay the work must be carefully done. The accompanying illus- 

 tration, figure 63, shows the various stages in filling a knot- 

 hole cavity. Briefly stated the work consists in cleaning out 

 all the decayed material, sterilizing with copper sulphate so- 

 lution, and filling with concrete. The edges of the wound 

 should be trimmed back to living bark. Knot-hole wounds are 

 usually prepared by sawing off the projection or lip around the 

 wound. If the decayed area has not extended far enough to weaken 

 the tree, the cavity need not be filled. It should be cleaned and 



