Blue spruce, known botanically as Picea pungens, is a species of needled evergreen trees and shrubs also commonly called Colorado spruce. The species is known for a distinctive blue to blue-green hue to the needle foliage. This color is derived from a combination of the foliage tissue itself and a whitish-blue powder coating that further enhances the needles' color. The blue color can be preserved and enhanced by a few cultural practices and careful protection of the plant needles from abrasion of any kind.
Things You'll Need
Secateurs or loppers
Fertilizer for acid-loving plants
Position the trees or shrubs in a full-sun exposure; this maximizes photosynthesis activity, giving each cultivar the brightest possible blue hue.
Water the trees sufficiently year-round, deeply wetting the root ball, so that they are never under the drought stress that can cause the needles to become desiccated, scorched and brown. Water at the soil line, and never shoot water at the branches, as this can reduce the powder needle coating and diminish the blue appearance.
Protect the trees from heavy snow or ice buildup in winter that can scrape off the powder coating on the needles, thereby reducing the bright blue hue of the foliage. Gently shaking off heavy snow buildup periodically, leaving only a light protective coating of snow, can help to prevent this.
Fertilize your blue spruce with a complete, slow-release fertilizer formulated for acid-loving evergreens or other acid-loving plants. Apply according to the dosing directions on the label. Repeat yearly.
Refrain from rubbing or handling the needles and branches, as this can also rub off the blue-white coating that makes the tree appear so blue on the landscape.