Questions About Blue Spruce Trees

What Does a Blue Spruce Tree Look Like?

• The blue spruce is a conical-shaped conifer. It has a single strong trunk and long branches that grow almost perpendicular to the trunk. Stout yellow-green twigs support evergreen needles that grow at right angles to the twigs. The silvery to blue-green needles are sharp, stiff and about 3/8 inch to 2 1/2 inches long. Every two or three years, the blue spruce produces elliptical seed cones that start out green or violet and mature to a pale tan. The bark of the blue spruce is thick and gray-brown in color. As the tree grows, the bark breaks into furrows and ridges.

Where do Blue Spruce Trees Grow?

• In the United States, blue spruce trees grow in the east from the mid-Atlantic states to Maine. In the west they grow from north to south from the Canadian border to the Mexican border, including in the states of Idaho, Wyoming, Utah, Colorado, New Mexico and Arizona. Blue spruce trees do best in United States Department of Agriculture hardiness zones 2 through 8 at elevations of 6,000 to 10,000 feet.

How Tall do Blue Spruce Grow?

• At 20 years, a blue spruce tree is about 20 feet tall. At maturity, it is 100 feet high. It grows slowly and can live for up to 600 years.

What Growing Conditions are Suitable for Blue Spruce Trees?

• Blue spruce grows in medium to coarse textured soils with a pH of 5.5 to 7.8. This tree needs a minimum of 20 inches and a maximum of 45 inches of rain each year. It cannot survive at temperatures below -38 degrees Fahrenheit. It has a medium tolerance for drought conditions and a low tolerance to salt.

To What Diseases are Blue Spruce Vulnerable?

• Blue spruce are vulnerable to cytospora canker of spruce, a fungus that attacks older trees stressed by environmental conditions. The canker causes branches, usually lower branches, to die. The best strategy is prevention; failing that, aggressively prune affected branches. The other disease blue spruce is susceptible to is a disease that affects the needles and is caused by the Rhizosphaera fungus. This fungus causes the needles to turn purple or brown and eventually die. If enough needles die, the branches will begin to die as well. The cure for this disease is to spray the infected tree with a fungicide in late May and then four to six weeks afterward.