

Specimen Koster Blue Spruce in the Hill Nursery 
22 

Matured specimen of Koster Blue Spruce 
Koster Blue Spruce 
(Picea pungens kosteri) 
Glistening Silver Blue in Color 
EW Evergreens have obtained the popu- 
larity of the Blue Spruces. The seedling 
form known as the Colorado Blue Spruce 
(Picea pungens glauca) is native to an extensive 
region in the Rocky Mountains, extending from 
New Mexico north, most extensively in Colorado. 
It is a magnificent tree in its native stands. 
Those of the most bluish color are found in deep 
gorges of high altitudes. 
When planted from seed, a small proportion 
of the trees develops the bright blue color. The 
great majority are of greenish cast, or only a 
slightly bluish tendency. The form which is 
most generally planted and for which greatest 
demand exists, is the selected trees with the 
bright blue foliage. Like many of 
the highly-colored Evergreens, this 
bluish color is a bloom or sheen, 
a sort of powdery substance on 
the outside of the needles. For this 
reason its color is less pronounced 
during the winter months, and 
brightest during the late spring and 
summer. 
While the seedling form makes a 
beautiful and symmetrical tree, it 
is but seldom that an unusual blue 
specimen develops. For this reason, 
many of the more choice trees to 
be seen in plantings are one of a 
number of selected horticultural 
varieties which have been propa- 
gated by grafting. 
Chief among these is the Koster 
Blue Spruce, a variety of many 
years standing, originally selected 
and propagated by one of the lead- 
ing nurseries of Holland, which 
name it bears. Grafted trees are 
uniform in color, all reproducing 
bright blue color. 
