The blue spruce, also commonly known as the Colorado blue spruce, is a popular coniferous evergreen tree known for its powder blue needles. Known scientifically as Picea pungens, the blue spruce is native to North America and is found growing in the south and central portions of the Rocky Mountain range.
Blue spruce growing in the wild will attain a height of 80 to 100 feet tall and a width of 20-30 feet depending on the elevation and precipitation that it receives throughout its life. This species is long-lived with specimens found that were estimated to be 300-600 years old. The needles of the blue spruce are ¾ to 1.25 inches long and are very stiff and sharp at the points. The blue coloring on the needles comes from a coat of white wax over the needle’s true color of medium green which gives it a blue cast. The bark is a grayish-beige that is patchy and flaky in appearance. Cones of the blue spruce appear in the fall and are golden brown. The cones are produced on the underside of the upper branches and are 2-4 inches long.
Because it is native to higher elevations and harsh mountain conditions, the blue spruce is very hardy and adaptable and is listed as able to thrive in USDA zone 3. Although it grows best with adequate moisture during the spring and summer, the blue spruce is adapted to grow on mountain slopes that receive little to no rainfall during the summer making this tree a drought tolerant species. It is also adapted to withstand very cold temperatures of below freezing along with snow and wind.
This type of spruce produces brittle wood that is often full of knots making it an undesirable species for timber. It is, however, an extremely popular choice as an ornamental tree. The blue spruce is most commonly used in landscapes and gardens around the world in temperate regions. There are over a dozen cultivars of blue spruce that are strictly ornamental and are considered living sculptures. The blue spruce is available in weeping and cascading forms, upright forms, globular forms, dwarf forms, and even as a creeping ground cover. All of these cultivars have beautiful bright blue needles and look stunning when planted with other ornamental plants that provide contrast and texture. All of these cultivars stay much shorter than the straight species and rarely attain a height of more than 50 feet (for the upright forms). The blue spruce is also a popular choice as a Christmas tree as it grows in a very uniform conical shape that needs little to no shearing.
A very pretty tree, the blue spruce is a favorite for both gardeners and wildlife alike. Planting an ornamental variety of blue spruce will not only give the garden year round color, texture, and interest, but will also provide food and shelter for birds, insects, and other small mammals and reptiles. Spruce seed are a favorite of many species of birds and small mammals and the dense, sturdy branches are perfect for nesting and winter protection.