826 The Trees of Great Britain and Ireland 



These have been planted seven years, and though for a time the Colorado held 

 their own with the spruce they are now being left behind." 



" We have raised some millions of the Oregon variety and find it sufficiently 

 hardy for all practical purposes. It does frequently make a second growth in the 

 nursery stages, and these may be killed back, but the damage done in this respect is 

 not serious. After being planted out and established in the plantation, they are 

 capable of bearing a greater degree of exposure than the Norway spruce, and may 

 be seen on the lower spurs of the Grampians easily beating the latter. In the 

 treeless district of Buchan it does not do well, but neither does any other tree ; 

 but for general planting in Scotland, and with ordinary precautions, it is quite 



valuable." 



" A member of an old firm of nurserymen informed me that it is about fifteen 

 years since the Colorado variety first began to be sent to this country in quantity, 

 and they only found out the mistake after the seedlings came up. To speak of 

 the Colorado as 'glaucous' and the Oregon as the green variety would be 

 incorrect, as both vary in colour. The Colorado may be found of all shades from 

 green to a rich glaucous, while the Oregon runs from a dark bluish tint to a light 

 green." 



A most striking instance of the different rate of growth of the two trees may be 

 seen in Dr. Watney's avenue at Buckhold in Berkshire, where Oregon Douglas 

 about 3I feet high were planted in the winter of 1882-83, in trenched ground on 

 a gravelly soil with some clay, underlaid at a depth of 10 to 12 feet by chalk. Five 

 of the best of these average in 1908 59 feet 8 inches in height by 4 feet in girth. The 

 largest was 65 feet by 5 feet 3 inches, showing 2^ feet of annual height increase for 

 twenty-four years. Colorado Douglas (so-called) planted on the same land at the 

 same time, were, when I saw them, not above half this size. 



In the Great Bear plantation, on the same estate, planted October 1895, and 

 steam cultivated 15 inches deep. Dr. Watney has measured six average Colorado 

 Douglas, planted about 3 feet high, now 1 3 feet by 6f inches ; six average Scots 

 pine, planted about i^ feet high, now 18 feet by 12 inches ; six average larch, planted 

 about 2 feet high, now 19 feet 7 inches by 9^^ inches. According to his experience 

 the Colorado have many small branches which extend but a short distance from the 

 stem, whilst the Oregon are distinguished by wide-spreading branches set much 

 farther apart on the stem. He says that the latter is the fastest-growing tree he 

 knows, whilst the former is probably the most useless of all the common conifers he 

 has grown ; and yet he is told by a leading nurseryman that about one-third of the 

 seed he buys produces plants which are apparently of the Colorado variety. These 

 trees are sold and planted somewhere, to the great ultimate loss and disappointment 

 of the unwary planter. 



The Douglas fir is usually healthy and little liable to insect or fungus attacks. 

 However, of late years, a fungus, Botrytis Douglasii, Tubeuf, which is known as 

 the Douglas fir blight,^ has caused considerable danger to young trees growing in 

 nurseries. The leaves, especially those on the upper shoots, wih and fall off; and 



1 Fisher, Schlich's Man. Forestry, iv. 461 (1907). 



