Colorado Blue Spruce (Picea pungens var. glauca) This large evergreen with a moderate growth rate can reach heights of 100+ ft. It has short, stout, prickly, bluish green to bright, silvery blue needles. Prefers fertile, moist soil in full sun, but will tolerate dry, well-drained areas as well. Valued as ornamentals, windbreaks, and Christmas trees.