The Colorado blue spruce (Picea pungens Glauca) is a North American native conifer, hailing from the Rocky Mountains. Growing to a height of 70 to 90 feet, with a 20-foot spread, the Colorado blue spruce is slow-growing and easy to care for. The tree derives its name from the silver needles that have a blue cast. Planted as a specimen or in groups to provide a windbreak, the Colorado blue spruce does best within USDA hardiness zones 2 through 8.
Water the Colorado blue spruce during periods of drought. Place a soaker hose at the base of the tree and allow it to run for three to four hours.
Remove all weeds, as they appear, from within a 2-foot radius of the tree's drip line.
Keep the Colorado blue spruce tree's roots cool and moist by placing a 3-inch layer of mulch on the soil beneath the tree. Keep the mulch 3 inches from the trunk and spread it out 1 foot beyond the drip line (the soil beneath the widest part of the tree's canopy).
Fertilize the Colorado blue spruce in the spring with a 10-8-6 NPK formula, at the rate suggested on the package for the size of your tree. Spread the fertilizer on the soil beneath the tree and out to the drip line. Rake the soil lightly and water as you normally do.
Inspect the Colorado blue spruce for spider mites during hot, dry periods. Sometimes just spraying the tree with a hard jet from the hose will knock them off. If that fails, apply insecticidal soap to control the pests. Apply at the rate suggested on the label.