THINNING. 117 



lower branclies too far. To counteract this tendency, 

 and to thi'ow the strength of the tree into the main stem, 

 the terminal bud or shoot of the lower branches is to be 

 pinched off. Cedars and other spreading firs, treated in 

 this way, may be made to assume an upright form. 



Tliinning. — Thinning is an operation nearly as neces- 

 sary as pi-uning, and in fir plantations perhaps the more 

 necessary of the two. As young woods are generally 

 planted more densely than is needful for their permanent 

 condition, in order that the young trees may produce a 

 shelter for each other, and a con-esponding warmth in 

 the climate, the period selected for thinning the young 

 plantations should vary with the progi^ess of the trees, 

 as that again wiH vary with the soil and climate in 

 which they grow. Some plantations may receive a par- 

 tial thinning by the time they have been seven or eight 

 yeai^s planted ; others in more exposed places may not 

 require the same sort of thinning till they are double 

 that age. 



In the process of thinning it should be distinctly kept 

 in mind that the trees which are removed were originally 

 planted to shelter and di'aw up the ti'ces which are to 

 remain, and that only those are to be cleared away fi-om 

 time to time which are doing injmy to those designed 

 to be permanent. TMien this principle is made to regu- 

 late the work, there is little danger that thuming will be 

 carried to an injmious excess. Kothing is more preju- 

 dicial than excessive thinning. The bark of those trees 

 which have been well sheltered by close planting is less 

 dense and more sensitive to cold than that of trees ex- 

 posed to all weathers, and their roots are much fewer 

 and have a slighter hold of the groimd. It is evident, 

 therefore, that the trees left standing in over-thinned 



