518 



HORTICULTURE 



April 21. 1906 



and very little pruning is necessary aside from keeping 

 ree from dead twigs and branches. This rule 

 will hold good in the eases of such trees as naturally 

 grow in a graceful form, as for example; the beeches, 

 elms, rock maples and many of our conifers. On the 

 other hand, various other varieties such as the sofi 

 maples need continued attention in order to make them 

 attain a shape conducive to the greatest strength and 

 uty. 



It is essential in the operation of pruning, that a cer- 

 tain definite purpose should he held constantly in mind. 

 Pruning for the mere sake of pruning has no place in 

 the gardener's program. Just what to cut and what to 

 leave, for the good of the tree, requires study, and not 

 until the ideal is formed is it time to use the saw. It 

 is well to begin at the top of the tree, first relieving it 

 of all dead branches and lowering the larger limbs in 

 sections, making the final cut in every case in a line 

 with, and as nearly even with the trunk as practical, 

 this being done in order to make the cambium sur- 

 rounding the wound in the path of a downward flow of 

 the elaborated sap, since this insures rapid healing. 

 Where practical, it is well to make the cut perfectly 

 even with the trunk, but in isolated cases such a method 

 produces an unnecessarily large wound, when by a 

 slight deviation from this line a much less severe cut 

 may be made and one which will not detract from the 

 appearance of the tree after the healing has taken place. 

 In general, enough live wood should be removed to give 

 to the tree a well-balanced effect, to allow an even dif- 

 fusion of sunlight and air, and to provide for a free and 

 easy growth of the remaining branches. It is often the 

 case that in many young trees, as for example the horse 

 chestnuts and soft maples, an over abundance of inner 

 growth is formed to the detriment of the tree; this 

 should be thinned out severely, in order that the vigor 

 of growth may be thrown into the leader and main 

 branches. 



Where two limbs interfere with each other the least 

 important should be taken out, as natural grafting, 

 although desirable in certain instances as a means for 

 holding together a weakened crotch, is generally harm- 

 ful from the fact that the graft is imperfect and an 

 impaired circulation of sap is resultant. 



On the trunks of many oaks and American elms an 

 unnatural growth known as "feathering" is often pro- 

 duced. This condition results from the springing into 

 growth of latent adventitious buds, and is caused by 

 some irregular condition of the tree. When once 

 feathering is thoroughly established a large leaf surface 

 is produced, which diverts the upward flow of crude sap. 

 elaborates it and uses It for the development of its own 

 system to the detriment of the remainder of the tree. 

 The large size and dark color of the leaves upon these 

 growths, as contrasted with 1 hose of the rest of the tree, 

 is oftentimes very apparent. Although the effect ren- 

 dered by these irregular growths is picturesque, they 

 should i>e removed, especially in cases where the tree 

 shows a tendency to decline in vigor. 



It may be set down as a prime requisite in pruning 



that all wounds should 1 vered with some water and 



; ii pri para! on in order to prevent checking and 

 to exclude the spores of fungi, which if given free 

 access will produce certain decay. Many dressings have 

 been tried with vari [< rees of success. For rough 



work in summer perhaps coal tar is preferable, owing 

 to its cheapness, the ease by which it is applied, and its 

 antiseptic properties. However, its color is disagree- 

 able and very seldom matches the color of the surround- 

 ing bark, and in many cases it is objectionable to use 

 about houses. 



Perhaps the best treatment for the larger wounds is 

 to apply a thorough coating of some antiseptic, as cor- 

 rosive sublimate, or creosote, followed when dry by a 

 heavy coat of good quality lead paint of an inconspicu- 

 ous color. The larger wounds should be repainted from 

 time to time until they are completely healed over, and 

 in order to hasten the process of healing the edge of the 

 surrounding cambium should be slit perhaps once a 

 year to prevent its becoming bark bound. Upon the 

 amputation of dead limbs it will be found that in many 

 cases the decay has penetrated into the trunk to such 

 an extent that even the most thorough applications of 

 antiseptics will not destroy the rot-producing fungi ; 

 and to simply paint over such wounds does not prevent 

 the destruction of the affected wood. In such instances 

 the decaying material should be carefully chiseled out 

 until sound wood is encountered, the cavity thoroughly 

 treated to an antiseptic and painted. In a majority of 

 cases this is sufficient to prevent further decay, but 

 where the cavities are deep or so shaped that they will 

 hold water, or where they are so large as to materially 

 weaken the branch it is necessary to fill them with a 

 substance which will exclude the water and air which in 

 the later case will furnish a mechanical support. 



For this purpose there are a number of brands of 

 elastic cement upon the market, which although they 

 furnish but little mechanical support to the branch, 

 cling tightly to the surrounding wood and are effectual 

 in repelling moisture and decay. A mixture of 

 asphaltum and sand, the cement of the ancients, may 

 be used to advantage in cavities where the constant 

 force of the wind would tend to crack and break a hard 

 setting material. For small holes putty, melted paraf- 

 fine or grafting wax may be used successfully. In more 

 severe ease- where tin' heart wood of the trunk or 

 larger limbs has become decayed a filling of Portland 

 Cement concrete reinforced, where necessary, by steel 

 liars has proved to be the best method of preserving 

 large trees from breakage or further decay. 



It is only on trees of considerable value, reckoned by 

 their size, associations and environment that thia kind 

 nf work is practical, and therefore when attempted 

 should be done with the greatest care, the same rules 

 being applied as are followed by a dentist in filling a 

 tooth, viz., a thorough cleansing, disinfecting and the 

 procuring of a perfect union between the filling mate- 

 rial and the cavity surface. 



In removing the decayed heart wood care should be 

 used to disturb the living laver as little as possible. 

 This can be facilitated by the use of long handled 

 gouges and adzes. Owing to the fact that the micilia of 

 the rot-producing fungus penetrates deeply into the 

 apparently sound wood much of the latter should be 

 removed. The cavity should be made to slope inward 

 ami a\\a\ from the opening at the top and sides of the 

 cut in order to better hold the filling in place, and 

 should slope upward and inward at the bottom to pro- 

 vide for drainage in case any moisture should collect in 

 or behind tin"' tilling. 



The inner surface of the cavity is then treated to a 

 eoat nt creosote, diluted copper sulphate or corrosive 

 sublimate and painted with two coats of heavy lead 

 paint. Tn hold the filling firmly in place, large sized 

 nail- are driven into the inner surface of the cut at a 



