They are 4-sided and have a very sharp point on the end. Needles are generally dull bluish-gray to silvery blue and emit a resinous odor when crushed. 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.