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 34 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 24 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 13 feet by 62⁄3 inches; six average Scots pine, planted about 11⁄2 feet high, now 18 feet by 12 inches; six average larch, planted about 2 feet high, now 19 feet 7 inches by 91⁄4 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, wilt and fall off; and
1 Fisher, Schlich’s Man. Forestry, iv. 461 (1907).
