The cultivated variety 'glauca' is noted for this type of coloration. Needles occur on small peg-like structures on the twig called sterigmata. The sterigmata persist on the twigs after needles have fallen, which is usually after the third or fourth year. Pollination occurs in late spring and cones mature in one season. In the fall, cones are 2-4 inches long and turn chestnut brown with stiff, flattened scales.
Cones generally persist on the tree for one to two years after seed fall.
The bark is thin becoming moderately thick with age. It is somewhat pale gray in small flattened scales when young, then turns reddish brown and furrowed with age. Blue spruce is moderately shade tolerant and grows best in deep, rich, gravely soils, often along stream banks and other sites with high moisture levels. It usually does not occur in large stands but is found in small groves or in association with Douglas-fir, lodgepole pine, Engelmann spruce or ponderosa pine. A deep penetrating root system makes the species resistant to being blown over.