TREE PROTECTION 25 



Raw bone meal is a good fertilizer for most trees and may be applied either 

 on a plowed surface or in drilled holes. It becomes available slowly and appears 

 to do no injury even when used in large quantity. In applying all nutrients care 

 should be exercised not to overfertilize trees, else root burning may result and 

 more harm than good be accomplished From the fertilizers applied to he soil, 

 only those substances which are water soluble and can be absorbed by the root 

 hairs will have direct nutritional value. Hence, the presence of water is always 

 necessary in any successful fertilizing program. The retention of water and other 

 substances in the soil may be facilitated by the application of mulches. Such 

 practice is of particular importance in the case of evergreens. 



Treatment of Wounds. Wounds on limbs and trunks of trees occur in a variety 

 of shapes and sizes. Those which result from the fracturing of a branch usually 

 have irregular and jagged margins. All wounds which can be shaped so that the 

 longer axes are parallel to the grain of the wood and which may be brought to 

 points at the extremities, are likely to heal more satisfactorily and to appear less 

 ugly than wounds not so treated. Final cuts of the wound margin should be made 

 so as to provide opportunity for callus growth (Fig. 5, B) and for drainage of 

 water. 



When the outline of the surface to be treated has been definitely determined, 

 all rough and loose edges of bark should be removed with a sharp chisel, and 

 shellac applied with a small brush. The shellac will prevent drying out of the 

 narrow exposed moist layer of the inner bark. When this step has been carefullj' 

 completed, the wood surface of the wound should be made smooth and treated 

 with creosote, creosote oil, or other sterilizing agent; and with coal tar, asphalt 

 or other materials for protection. Creosote is inflammable and should not be 

 permitted to come into contact with an open flame. The creosote should be 

 applied only to the cut wood surface, with particular care to avoid the living 

 inner bark previously covered with shellac. 



Good wound dressings or paints are possible substitutes which may be used in 

 a single apjilication provided the precautions previously outlined are observed. 

 Asphalt without creosote is an excellent protective covering for wounds. The 

 necessity of applying it hot doubtless explains why it is not more widely used. 

 An emulsion of asphalt and water is obtainable commercially and the use of this 

 preparation eliminates the necessity for heating. This material may be applied 

 in the same way as wound paint. The water soon dries, leaving an asphalt 

 covering. 



The application of tar mixtures and creosote may cause severe injury to cer- 

 tain trees including magnolias, tulip-trees, and ornamental Primus species. For 

 these, other treatment is advisable, even though kss permanent in character, 

 and the following sterilizing and protective materials are sometimes used: liquid 

 wax, shellac, corrosive sublimate (bichloride of mercury), copper sulphate, spar 

 varnish, grafting wax, good commercial Bordeaux paste, Bordeaux powder mixed 

 with raw linseed oil, and water glass (sodium silicate). 



In applying all protective coatings, care must be taken not to cover the un- 

 injuied bark about the wounds. Frequently, recoating of treated surfaces may 

 be necessary after a year's time, and blistering, cracking, or checking should be 

 corrected as soon as detected. Careful attention to these details may preclude 

 additional serious injury. In all cases, individuals contemplating the use of 

 materials on trees should inform themselves thoroughly concerning .the nature 

 of these materials and their proper handling, including the need for precautions 

 against possible injury to persons and property. 



