58 PLANTING. 



to every soil and site alluded to. Where the local demand for the smaller 

 sized products of plantations are great, the more expensive process of 

 trenching should be adopted, inasmuch as the growth of forest-trees to the 

 size of poles, and of materials for fencing, &c., is highly promoted by 

 trenching and manuring, and the returns of profits from these products 

 of planting are in proportion earlier and larger. That this superiority 



mis in thf same proportion to the ultimate produce of timber in 



3, may not appear so clear, because it may be urged by those who 

 undervalue trenching and manuring as preparation of the soil for 

 planting forest-trees, that there are no satisfactory records of the com- 

 parative rate of increase of timber, or of solid vegetable fibre, after the 



tuenty or thirty years' growth of the different species of forest-trees, 

 which have been planted on trenched and manured grounds, and the 

 contrary, being under all other circumstances the same until their last 

 _<({ perfection; and yet the truth of such continued superiority of 

 increase, is the only test by which the question can be decided, and 

 an unerring rule of practice be obtained. The results of mere observation, 

 or conclusions drawn from the apparent contents of trees, will not be 

 found to warrant the adoption of any new mode of practice. But the 

 comparative increase and ultimate produce of timber should be ascertained 

 up to the period of the trees attaining to perfect maturity in the most 

 satisfactory manner, by actual admeasurement ; and correct records kept 

 of the age of the trees, comparative value of the plants when planted as 

 to their size, roots, and constitutional vigour at the time of planting; as 

 also the intimate nature of the soil, subsoil, and local climate. In the 

 oak, after the first fifty or sixty years' growth, the annual rate of increase 

 of the diameter diminishes greatly. The Lambert pine-tree (Pitius 

 Lambertiana), mentioned in the IVttftf. Linn, tiocicfy, vol. xv. p. 497, 

 exhibited an increase of diameter of four inches and a half only at the 



, during the last fifty-six years of its growth. 



These la^t remarks apply to the question generally ; but in all cases of 

 exception before mentioned, and in the instances of clayey, tenacious soils, 

 and compact gravelly loams, trenching ought doubtless to be adopted as a 

 preparation for the reception of forest-trees*. 



* The advantages of trenching have been zealously and ably advocated in a late publi- 

 cation by Mr. \\ithers, to which we have already referred, and the proofs brought forward 

 in support of h;s aiguments are satisfactory as far as they go : but the must important 

 in- those of the superior increase, and the comparative quality of the timber when 

 thi' !: .ttained to fullmatiirit- rs 01 the facts staled by Mr. Withers, 



continued until the trees attain to full timber sue, and of the buildings or pur- 

 to which, in cert he timber is applied, are what would atibrd invaluable 



information, and for which posterity would be grateful. A distinguished writer assorts 

 that after the first twelve or twenty years of growth of trees planted on land prepared by 

 trenching, all distinction is lost between the 'iji/inrrtif growth of these and of those which 

 ; inted by the simple process of holing. In general cases, the observations 

 of the writer of this have led to precisely the same conclusions. It is improbable, how- 

 ever, that the superior growth which so distinctly marked the progress of the plants on the 

 i.ed ground during the first years of growth should wholly cease, but that it diminishes 

 ;1. whi.-h had been loosened by the process, becomes consolidated to 

 and in proportion as the roots advance in the subsoil which had remained 

 equally undisturbed in the execution of both modes of preparation, is quite certain. 

 Whether this superior iae of pn !i reduced in degree, continues until the tree 



1 maturity. 'hat period. ritainly no records of 



<>f wood in trees, different 



y in this particul;ir. The locust, for instance, will make shoots of six feet in 



'h for a few of ti \vlh.or. it cut down when in abcalthy state, 



in one season shoots of thi> but to conclude from 



.rcumstance that the locust is one of the fastest growing trees, or even that it is equal 



in this respect to the blow growing oak, would be erroneous, inasmuch as. at its fifteenth 



