166 SYLVICULTURAL NOTES ON 



accommodating as to soil, but does best on a deep, fresh, sandy 

 loam ; it also does fairly well on stiff soils on the slopes of 

 hills where there is a good natural drainage. It does not 

 thrive on chalks or limy soils, or on dry soils. It can be 

 grown in high forest as a pure wood, as it is soil improving ; 

 or it can be mixed with larch, preferably in groups ; when 

 mixed with other species it will probably outgrow and sup- 

 press them. It may be used for underplanting larch or other 

 light-foliaged trees. When grown pure it should be planted 

 at not more than 4 feet apart as, unless grown closely, the 

 branches will not fall off early. At present, Douglas fir plants 

 bought from nurserymen are very expensive, and it is far 

 better to grow them from seed in the home nursery where 

 they can be raised quite cheaply, with no difficulty. 



The timber is of much the same character as that of larch, 

 but ranks between it and Scotch pine in value. It is largely 

 imported under the name of ' Oregon pine '. Although of less 

 value than larch per cubic foot, it will possibly pay better, 

 as a very much larger quantity can be grown on an acre. 



It has not suffered in Britain to any great extent from 

 insects and fungi, but a fungus, Botrytis cinerea^ attacks the 

 foliage of young plants in the nursery, while Phoma pithya 

 causes cankerous disease on the twigs and branches. These 

 fungi may increase and do serious damage. The pine weevil 

 (Hylobius abietis) and the cockchafer seriously injure young 

 Douglas fir, and other insects attacking conifers may spread 

 to this species. 



The Colorado variety is a much slower growing tree and is 

 not worth planting on a large scale, at any rate in the south 

 of England. It suffers considerably from spring frosts, and 

 appears to grow best when under an existing crop of larch, 

 oak, or other lightly foliaged tree. It may therefore prove 

 of use for underplanting. Care should be taken when pur- 

 chasing Douglas fir to see that this variety is not supplied in 

 place of the green one. 



