Ornamental and Shade Trees 



A Department for the Advice and Instruction of Members of the American Forestry Association 



REINFORCING TREES 



By Harold J. Neale, City Forester, IVorcester, Mass. 



IT [S an accepted fact that shade trees on public streets 

 increase property values. This of course is in pro- 

 portion to the size and condition of the trees as a 

 small tree would not increase values very greatly while 

 an old, weakened tree would be about in the same class, 

 as far as value is concerned. The question arises then 

 is it not possible to make, these old trees safe and elim- 

 inate their weaknesses? They are the heritage of gen- 

 erations past and are a necessary adjunct to old settle- 

 ments ; as in Xew Eng- 

 land where we have old 

 colonial mansions with 

 beautiful spreading elm 

 trees as their proper 

 setting. 



On private lands 

 these trees, set out 

 many years ago, have 

 had a free and easy ex- 

 istence and are in many 

 cases sound and free 

 from any weakness. 

 The street tree of the 

 same generation, how- 

 ever, has had a different 

 battle to fight. Hitching 

 horses to a ring bolt 

 fastened into the trunk 

 of these street trees or 

 by throwing the reins 

 around the trunk was 

 not uncommon and 

 was. of course, an in- 

 vitation to the animal 

 to gnaw and thus injure 

 the bark on the trunk. 

 This was immediately 

 followed by the en- 

 trance of fungus diseases, causing deeay and the gradual 

 permeation of the mycelium or root hairs of the fungus 

 which today leaves an ugly scar extending in many cases 

 through the heart of the tree. This presents a proposi- 

 tion to the city forester or tree man. It is the proper 

 procedure for making the thoroughfare safe for pe- 

 destrians. 



With the aim of saving the old trees, making them 



safe, sound and healthy the arboriculturist of today is 



striving quite as much as he is in the planting of new 



trees for future generations to enjoy. Bolting insecure 



42 



A METHOD OF TREATMENT 



An elm which, despite its injuries, is still of value and worth preserving. If an 

 attempt had heen made to remove the decayed portions without reinforcing the 

 trunk, the tree would probably have blown down, so an iron cable was fastened 

 as shown in the right hand picture and tightened sufficiently to allow for the 

 swaying of the trunk. The decayed portion was then removed and the cavity 

 treated. 



limbs, chaining them and similar measures have been 

 practiced for a number of years. In New England we 

 see many large elm trees girdled by heavy iron bands 

 which were improperly placed. In other cases heavy 

 chains have been placed around limbs, not girdling them, 

 but causing the bark to die on the side in contact with 

 the chain. In some cases the bark and the cambium 

 cover the chains, embedding them into the heart wood 

 of the limbs and they cannot be discerned. 



The process of bolt- 

 ing, although not diffi- 

 cult, requires a certain 

 amount of study and 

 care. Mechanical 

 forces must be taken 

 into consideration. The 

 stronger of the limbs 

 to be bolted must be 

 used for the support 

 and the bolt placed at 

 right angles to the side 

 of the weaker limb, 

 otherwise the weaker 

 does not receive the 

 maximum pulling 

 forces of the bolt, to 

 hold it in place. In the 

 case of a split tree the 

 forces must be divided 

 so that each limb is ex- 

 erting an equal lever- 

 age on the other. The 

 bolt must be placed as 

 high as possible in 

 order that it will be 

 able to exert a maxi- 

 mum amount of ten- 

 sion with a minimum 

 amount of energy. A bolt, however, should not be placed 

 high enough to allow any swaying of the limbs, which 

 would have a twisting effect on the bolt which would in 

 time weaken and break owing to its inelasticity. In case 

 this is necessary the bolt should be placed low and a chain 

 or cable placed higher. The size of the bolt is also an 

 important factor, and the growth of the limbs with their 

 increasing weight must be considered. The placing of 

 a bolt in a tree will not in all cases induce stronger 

 growth, but it is necessarily a permanent factor in hold- 

 ing the tree together, while in others a bolt may be placed 



