Blue spruce, also known as Colorado spruce, is a conical-shaped evergreen tree with stiff horizontal branches and short stiff needles. It is a commonly used tree in Midwest landscapes, although it has struggled with fungal issues as it ages. In nature the needles are often green, but many specimens produce blue-green needles. This tree is also known as Picea pungens ‘Glauca’.
Native geographic location and habitat:
It is native to the southwestern United States through the Colorado Rockies, Wyoming, New Mexico, and Utah.
Bark color and texture:
The bark is gray and broken into large scales.
Flower arrangement, shape, and size:
Male pollen and female cones that become woody when pollinated. Both male and female cones are found on the same tree.
Fruit, cone, nut, and seed descriptions:
The medium-sized cylindrical cones are 2 to 4 inches long and 1 1/2 inches wide. They are light brown in color and are often clustered near the top of the tree.
Attracts birds, pollinators, or wildlife:
Browsers, small mammals, songbirds are attracted to this tree.
Blue spruce grows best in full sun and requires good soil drainage and proper watering during dry weather. Plant specimens far enough apart to allow good air circulation. If planted in dense shade, needles will drop resulting in bare branches. It needs to be protected from drying winds. Blue spruce requires very little pruning. All evergreens experience seasonal needle drop and blue spruce needles will drop three to four years after emerging.
List of pests and diseases:
Blue spruce is prone to cankers, needle casts, spruce adelgid, spider mites, spruce budworm, and cytospora canker.
Baby Blue Eyes blue spruce (Picea pungens ‘Baby Blue Eyes’):
This semi-dwarf cultivar with blue-gray needles grows 15 to 20 feet high.
Baker blue spruce (Picea pungens ‘Bakeri’):
A more compact cultivar with deeper blue needles that grows 12 to 20 feet high and 6 to 10 feet wide.
Fat Albert blue spruce (Picea pungens ‘Fat Albert’):
A semi-dwarf cultivar with good blue color and a dense pyramidal form that grows 15 feet high.
Globe blue spruce (Picea pungens ‘Glauca Globosa’):
This tree grows only 3 to 5 feet high and 3 to 6 feet wide producing a neat, dense, compact, rounded shape. This cultivar is a good accent plant for foundations and borders. It seldom produces cones.
Hoops blue spruce (Picea pungens ‘Hoopsii’):
A dense, pyramidal cultivar with very good silver-blue color that grows 30 to 50 feet high and 15 to 20 feet wide.
Montgomery blue spruce (Picea pungens ‘Montgomery’):
This cultivar grows 5 to 6 feet tall and wide. Its shape is rounded when young and broad and conical when mature. The silver-blue needles add color to the winter landscape. It seldom produces cones.
Thomsen blue spruce (Picea pungens ‘Thomson’):
This cultivar with thick silver-blue needles grows 40 feet high and 20 feet wide.