PSC 2620: Woody Trees and ShrubCourse HomeWeek 13

Picea pungens var. glauca - Colorado Blue Spruce

Plant Viewer
The needles are a blue-green color and 3/4 - 1 1/4 inches long. They curve forward and are more numerous on the top of the branch. The bark is gray brown and forms in large plates on the tree.

Plant Description

Picea pungens, or Colorado Spruce, is a large coniferous evergreen tree, of which the most popular variety is Picea pungens var. glauca, or the Colorado Blue Spruce. It has a tight pyramidal form, growing slowly to 50-70 feet tall and 10-20 feet wide. In the wild it can reach twice that size. The branches are held out stiffly, with a very slight downward sweep. It is very adaptable to different types of soil and moisture conditions, and is one of the most drought tolerant species of Spruce. Plant in full sun for the best form and growth rate.

The bark is gray brown in color and matures to be very thick and corky. Large plates form on the trunk with deep fissures in between. The needles are blue-green, 3/4 - 1 1/4 inches long and stiff and prickly. They are more numerous on the upper side of the branch and curve slightly towards the end of the branch. The cones are an elongated oval shape and 2-4 inches long. They emerge green and can then turn a purple color before browning. The cone's scales have an undulating surface and a finely toothed margin once the cone opens.

Landscape Use

Colorado Blue Spruce can be used as an accent tree thanks to its clear blue foliage, which adds some interest and variation to the landscape. It is well suited to use as a wind break of visual screen, but should be mixed with other tree and shrub plantings in both instances. It is best if it is kept away from (or pruned up) walkways due to the prickly needles.

Points of Interest

Picea glauca is also very susceptible to spruce gall aphid, which creates brown galls on the tips of the branches. The galls are normally only an ornamental problem, but major infestations can stress the tree, causing it to grow slowly or become susceptible to other infestation. Spider mites can also be a problem.

There is a great deal of variation in the needle color of Colorado Blue Spruce. One specimen may be very blue, while another can be nearly green in color. Sticking with a cultivar propagated by cuttings is the best way to get uniform color across multiple specimens.

Notable Cultivars

Baby Blue Eyes
A very slow growing compact cultivar of Picea pungens var. glauca. It grows in a nearly perfect christmas tree shape. 12-15 feet high and 6-8 feet wide.



Fat Albert
Is a moderate sized pyramidal form of the Colorado Blue Spruce and grows 30-40 feet high and 10-20 feet wide. The needles have a very good and consistent blue hue.



Iseli Fastigate
A good columnar cultivar perfectly suited for a narrow space or as a screen or wind break. It has a cigar-shape with strongly upward arching branches. It grows 10-15 feet high and 5-7 feet wide.



Sester Dwarf
A very compact and dwarf variety. It grows very slowly and only reaches 8 feet tall and 4-5 feet wide. The needles are a vibrant blue color. It is an expensive plant because of its slow growth rate and the royalty fees established by Sester Nursery, which developed it.