PLANTING DISTANCE FOR DOUGLAS FIR. 9 



2. Planting Distance for Douglas Fir. 



By Brig.-Geneial Stirling of Keir. 



Sir Hugh Shaw Stewart has raised a question of great 

 practical interest in his observations on the planting of the 

 quicker-growing conifers, printed in the Transactions of the 

 Society for November 1920, 



Most planters who have experience of mixtures of Douglas 

 fir and Sitka spruce with slower-growing conifers will support 

 Sir Hugh's contention that the formation of such plantations is 

 in fact a waste of time and money. Sooner or later, according 

 to the distance apart of the fast-growing species, the Douglas 

 fir or Sitka spruce secure to themselves all the growing space, 

 and suppress the slower-growing trees, generally before they 

 have any value as thinnings, and without their having had any 

 appreciable effect in suppressing the side branches of the 

 dominant trees. The result after fifteen to thirty years of 

 growth may approach very nearly to what it might have been 

 if all the slow-growing individuals had been left out of the 

 mixture, and if the fast-growing species had been planted at 

 8 to 10 feet or more apart. 



These plantations have generally failed to realise the 

 expectations of the planter, but at least they have provided a 

 useful lesson. 



Before discussing the best planting distance for Douglas fir, 

 it is necessary to define clearly the object with which the 

 plantation is to be made, whether for the production of the 

 maximum bulk of pit-wood which can be grown on a short 

 rotation, or for the maximum return of timber of high technical 

 quality. Sir Hugh, in suggesting that Douglas fir should be 

 planted 7 feet apart, makes it clear that the object in his mind is 

 the production of pit-wood to be cut at a very early age, fifteen 

 to eighteen years after planting. The distance recommended 

 has an obvious advantage at the present cost of planting — it 

 is economical, and with good luck almost every plant may 

 survive to form part of the crop of pit-wood. With only 889 

 plants to the acre to begin with, the young plantation cannot 

 afford many blanks, and the beating up must be attended to 

 early if the replants are to have much chance of living to form 

 part of the crop. 



