August r, 1882.] 



THE TROPICAL AGRICULTURIST. 



?i5 



TREE PRUNING. 



C Translated from the French of A. de.s Cars, by Charles ,S'. 



SarrjenI, Professor of Arboriculture in Harvard Col- 

 lege, U. S.) 



Aim and Method of Pnming.—The object of pnming, 

 ecouoinically considered, is to make it possible to raise 

 on a given siu-face, say on one Inmdred acres of sprout 

 land, tlie greatest uuinber of fiill-gi-owu trees, and to 

 make them attain the gi-eatest value in the shortest 

 time without iiijm-y to the young trees beneath them. 

 This may be accomplished by increasing the vigour of 

 the reserve trees and by lengthening, without diminish- 

 iuf in diameter, theii' trunks. Treated in this manner 

 the reserve trees do not interfere with the cii-culation 

 of air and light necessaiy to the development of the 

 undergi'owth ; and many serious accidents caused to 

 trees by ivind, frost, and snow breaking the .larger 

 branches may be avoided by keeping their heads sym- 

 metrical and upright. 



The jiei-fect forest tree has a straight, single tnmk, 

 without protuberances or woimds, and carrj-ing up the 

 same diameter to tlie lirst branches, which should be 

 placed at ft distance from the gi'oimd equal to one-thii-d 

 or one-half of the total height of the tree. The head 

 should be rounded, regular, and set upright on the tmuk. 

 The wood, owing to the healthy growth of the tree, 

 is straight-gained, compact, and suitable for constrac- 

 tion. Such trees have a high value ; and, iu order to 

 grow them, a method of pi-uning is adopted similar to 

 that practised by gardeners in foi-ming pyi-amidal fniit 

 trees, with the difference, however, that the gardener 

 favom-s the development of the lower branches, which 

 are necessaiy for liis purpose, wliile the aim of the for- 

 ester is to increase foliage at the top of the tree by 

 diminishing the vigom' of the lower branches ; and to 

 obtain by "successive suppressions of branches the necess- 

 ary length of trunk. 



There are two distinct operations in pruning: the 

 removal of some branches, the shortening of others! 

 The shape of a tree must depend somewhat, of com-se, 

 upon its age, the natm-e of its sm-roundings, and the 

 character of the soil, &a. Where pruning is not pract- 

 ised, the reserve trees approach the proper form in 

 in'oportion to the length of time the coppice beneath 

 them is allowed to gi-ow. In forests, where thu-ty or 

 more years are allowed to elapse between the cuttings, 

 the undergrowth serves to pmne the pei-manent trees 

 l)v checking the development of then- lower branches, 

 aiid thus determining the height of then- tniuks. Sprout 

 land is, however, often cut over every ten years ; and 

 this practice prevents the production of fine trees by 

 permitting the growth of then- louver branches. These, 

 of course, interfere with the gi'owth of the reserve trees 

 themselves as weU as with the yoimg trees between 

 them. Judicious pnming can obviate this difficulty. 



Classification of Forest Trees accordinri to Aye. — The 

 technical names by which rcseiwe trees are knomi vai-y 

 in different regions. For our pm-pose it vnH bo best to 

 divide the life of a forest tree into fom- principal periods, 

 designated as follows : — 



1. Young, up to about forty years. 



2. Middle-aged, from forty to eighty years. 



3. Old, from eighty to one hundi-ed and iifty years. 



4. Veiy old trees, whose number is rapidly dimin- 

 ishing may be called veterans.* 



* The technical terms employed in France to desig- 

 nate trees of the four classes into which forest trees 

 are generally divided, Baliveau, Modcrne, Aneien, and 

 Vifilh's Kcorces, have no etiuivalent as yet, and are not 

 well translated into English. The tei-m " Baliveau " is 

 also sometimes applied to reserve trees of any age left 

 after the first cutting off of a plantation, and such trees 

 are then culled " Modernes," or ".\nciens," according 

 as they have been allowed to remain after a second or 

 third cutting of the coppice. — C. S. S. 



These divisions are not, of ooiu'se, absolute, as it is 

 often difficult to detennino, even approximately, the age 

 of a stauding tree ; and the forester must use consider- 

 able judgment in the application of the following luies : — 



1. The head of the yomig tree should be egg-shaped 

 or elongated oval, and well balanced on the tnmk, which 

 should not exceed a thml of the entire height of the 

 tree. The lower branches should bo sufficiently short- 

 ened to check then' excessive growth at the expense of 

 the leader, mthout, however, being so reduced as to 

 impau' the vigom' of gi'owth of the tree. 



2. The head of the middle-aged tree shoiUd foi-m an 

 oval less elongated than that necessary for trees of the 

 fii'st class. The height of the trunk should equal one- 

 thu'd to two-fifths of the height of the tree. 



3. The head of the old tree should be gradually 

 rounded iu outline ; the trunk may, in some cases, be 

 made to reach a height equal to half the height of the 

 tree, which has now probably ceased to gi'ow upwards. 



4. Veterans. — Trees classed as veterans have gener- 

 ally ceased to increase in -size. They gi-adually become 

 flat-headed, and spread out, without, however, gi-eatly 

 iujiu'ing the adjoining copinces and plantations destined 

 to take their places. 



The proper method of praning trees in each of these 

 fom' divisions will be considered hereafter. 



It is well to remember that the forms recommended 

 are those natm'e gives the most j)erfect and most beauti- 

 ful trees ; although it is the most economic and not 

 the pictm'esque aspect of trees which is here under 

 consideration. 



Tools used in Pruning — The most convenient tool for 

 pruning is a straight-bladed cleaving knife. Success in 

 all operations of pruning depends on the neatness of 

 the cut, and this cannot be attained with the common 

 billhook used in many parts of France. The best tool 

 for the pm'pose is one which has been used for many 

 years iu Holland, and which has lately been improved 

 by de Courval. It weighs from 2 lb. 12 oz. to 3 lb. 6 

 oz., or more, according to the strength of the work- 

 man. The blade is reuiforced in the middle to increase 

 its strength and concentrate the weight. In the mu'th 

 of France this tool is generally hung to an ii'on hook 

 attached to a leather strap buckled round the workman's 

 waist, who is thus left perfectly free iu liis movements. 



In pruning tall trees, or trees otherwise difficult to 

 climb, the leather belt may with advantage be passed 

 over the shoulder, thus bringing the pruning knife under 

 the arm in a position from which it cannot easily lie 

 dislodged in climbing. To ensm'e greater safety in climb, 

 ing tall trees, a stout cord attached to the workman's 

 man's waist may be fastened round the trrmk in such a 

 manner as to preveut, in case of accident, a dangerous 

 fall. A hatchet is useful, and facilitates the operation 

 of pnming^; it may be used with one or both hands, 

 and serves to lop off large branches, protuberances ou 

 the trunk, or the dead stumps of branches, which from 

 then' hardness would soon diUl the edge of the best 

 pruning knife. A saw, too, is veiy useful iu cutting 

 large branches, but it requii'es so much practice to nse 

 this tool skilfully that it cannot be generally recommended. 



Ladders. — Each labom'er should be equipped with a 

 light ladder, proijortionate to the height of the tree on 

 which he is to operate, and broader at the base than at 

 the top. De Com'val recommends that the foot of lad- 

 ders intended for this pm'pose should be pointed to pre- 

 vent them from sbppiug. This is a good plan, although 

 hardly sufficient to prevent accident, and the top of the 

 ladder should be fastened with a strong rope to the trunk 

 of the tree to prevent it from being thi'on-n dovm by 

 falling branches. 



Hooks or Spurs. — Except in very exceptional cases, or 

 where very lai'ge trees are to be operated ou, the climb- 

 ing spurs sometimes used by professional pruners should 

 not be allowed. These men, paiil according to the 

 nimiber of trees operated on or the quantity of woo^ 



