254 transactions of royal scottish arboricultural society. 



Planting Distance for Douglas Fir. 



In the last number of the Transactions of the Royal Scottish 

 Arboricultural Society a report is given of " A Discussion on 

 Economic Planting," held at the Annual Meeting of the 

 Society on the 20th January 1922 (vol. xxxvi. p. i). In this 

 discussion Lord Lovat referred to a plantation he had seen at 

 Avondale, Co. Wicklow, which he believed was spaced at 

 9 feet, but which had failed to produce satisfactory results. 

 As many planters are, doubtless, increasing the distance at 

 which they plant Douglas fir, it may be of interest to describe 

 the particular plot to which Lord Lovat referred, and note the 

 probable causes of its failure to produce clean timber. 



The plot in question is about 2\ acres in extent and was 

 planted in the spring of 1906, the mixture being 25 % Douglas 

 fir and 75 % European larch, planted 3^ feet apart throughout. 

 The Douglas fir was thus standing at 7 feet distances, or 886 

 to the acre. The situation is particularly well sheltered, and 

 the soil consists of alluvial sandy loam of considerable depth. 

 At the present time the Douglas fir is from 30 feet to 35 feet 

 in height, with stems girthing at breast-height from 20 inches 

 to 30 inches. The larch never throve after the first five 

 years, although a few individuals managed to get up, and are 

 now about 25 feet in height. The remainder are either dead 

 or suppressed. The failure of the larch was probably partly 

 due to the soil, which is very fine grained and close in texture, 

 but the trees were exposed to a series of exceptionally severe 

 frosts in the springs of 1906-1911, culminating in the last named 

 year with a frost on the 15th June which not only cut back 

 that season's growth on the majority of species, but also killed 

 a portion of the previous wood in low-lying situations. This 

 frost followed a warm May and early June, and scarcely a 

 Douglas fir shoot escaped injury or death. 



Although these frosts did not permanently affect the health 

 or vigour of the Douglas, they produced a very bad effect upon 

 their form. The leading shoots were repeatedly killed back 

 and replaced by shoots developed from lateral buds further 

 down the stem, or by branches forming the first or second 

 whorl. The absence of competition through the failure of the 

 larch intensified the evil, and although a complete canopy has 

 existed for several years, and every vestige of surface vegetation 



