2380 



ARBORETUM AND FRUTICETUM. 



PART III. 



this subject we refer to the history of the larch plantations at Athol and 

 Dunkeld, given at the end of this article. 



Thinning and Pruning. Where the object is timber of large size, the trees 

 ought to be thinned out soon after the brandies at the lower part of the 

 trunk interfere with one another to such an extent as to destroy all vegeta- 

 tion on the surface of the ground beneath them ; but, where they are intended 

 for poles, fencing, or other minor country purposes, they ought to be allowed 

 to stand thick, so as to be drawn up clean, slender, and straight. De Can- 

 doUe thinks the plantations of larches in Britain much too close. The 

 trees are generally at the distance of 3 ft. or 4 ft. from each other, which 

 is much closer than the Continental practice ; and he recommends double, 

 or even triple, that distance. Air and light would thus penetrate better 

 among the trees, and would correct the defects arising from the want of 

 evaporation, and the decomposition of the carbonic acid. You should not, 

 he adds, " begin planting at the distance of 10 ft. ; but you should begin thin- 

 ning out gradually, so as to bring your trees to the distance of 10 ft. apart 

 when 20 years old. Considering the atmospherical circumstances of Britain, 

 larch trees shoidd be at a greater distance than they are in Switzerland, 

 and yet they are at considerably less ; he therefore strongly recom- 

 mends thinning; and this recommendation, he says, is supported by the 

 judgment of the most judicious observers, viz., M. De Charpentier and 

 Emmanuel Thomas (the latter a nurseryman and seed dealer at Berg, in the 

 Canton de Vaud, and the former the author of a work on the Pyrenees). 

 These persons propose the distance of 1.3 ft., instead of 10 ft., from observing 

 what takes place in the Alps, where the larches generally make forests very 

 far from close. {Quart. Journ. of Agr., vol. v. p. 409. ; and Bihl. Univ. de 

 Geneve, Feb. 1835.) Very little pruning is required for the larch. Accord- 

 ing to Mr. Sang, the pruning of larch trees growing in masses, and intended 

 to attain a timber-like size, should be commenced about the sixth year of 

 tiieir growth ; and no more than one, or at the most two, tiers of branches 

 should be removed at a time, otherwise the trees will be nuich retarded in 

 their growth. After this, a tier of branches may be cut off" annually, taking 

 care that, in all larches 20 years old and upwards, not more than two thirds 

 of the trunk should be clear of branches. The branches should be cut off 

 close to the stem, in order that the wound may be speedily healed over by 

 the bark. The time of pruning is the winter season, when the sap is in its 

 least active state. The larch trees at Dunkeld seem scarcely to have been 

 pruned at all ; and, indeed, the tree having naturally only small branches, 

 which never attain a timber size, less pruning is required for it in a state of art 

 than for any other trees, except, perhaps, the spruce and the silver firs. Mr. 

 Pontey has shown, in his Forest Pruner, ed. 4., p. 71., by a diagram, of which 

 Jig. 2265. is a reduced copy, that even the dead branches of the larch, when 



2265 

 enclosed in the trunk of a tree, remain sound in it; and, consequently, when 

 the wood is sawn up into boards, it does not produce rotten knots, as is 

 frequently the case when dead branches have been enclosed by growing over 

 in the evergreen /Ibietinae ; and as always happens in similar cases with the 

 common broad-leaved trees. Fig. 2265. represents a piece of larch board, 

 taken from the root end of a tree above 2 ft. in diameter : a shows he core 



