Picea × albertiana
interior spruce
Overview
Picea x albertiana is a hybrid spruce, the cross of white spruce P. glauca and Engelmann spruce P. engelmannii, formed across a broad zone where the two meet in the interior of western North America. It is an evergreen conifer growing 60-100 feet (18-30 m) tall with a narrow, spire-like crown and a single straight trunk. The needles are four-sided, 0.5-0.9 inch (12-23 mm) long, blue-green to grey-green, and arranged spirally around the shoots; crushed needles give off a sharp, sometimes sour scent. Hanging cones 1.5-2.5 inches (4-6 cm) long mature from green to light brown in autumn and fall within the year, with thin, flexible scales. Trees vary in needle color, cone size, and hardiness depending on which parent they resemble. Growth is slow to moderate, adding about 1 foot (30 cm) per year. The shallow root system makes tall trees prone to windthrow on exposed sites, and lower branches thin in heavy shade.
Native Range
Native to the interior of western North America, through the Rocky Mountains and foothills of British Columbia, Alberta, and the northwestern United States. Forms extensive hybrid populations between the lower-elevation white spruce and the higher-elevation Engelmann spruce, in cool, moist montane and boreal forests.Suggested Uses
Planted as a specimen, windbreak, or screen in large, cool-climate gardens and rural shelterbelts, spaced 12-20 feet (3.5-6 m) apart. Used for winter shelter and nesting cover by birds. The eventual height of 60-100 feet (18-30 m) makes it unsuited to small lots or sites under power lines.How to Identify
Appearance
Size & Dimensions
Height60' - 100'
Width/Spread15' - 25'
Reaches mature size in approximately 30 years
Colors
Foliage Colors
Fall Foliage Colors
Bloom Information
As a conifer it does not flower. Pollen cones and small reddish seed cones appear in late spring, with the seed cones enlarging and hanging downward as they ripen to brown by autumn. Cones are shed within the year and bear no colorful display.
Detailed Descriptions
Foliage Description
blue-greenGrowing Conditions
Sun Requirements
Requires 6-8 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow in full sun in moist, well-drained, slightly acidic soil; growth slows and the form opens up in dry or shaded sites. Water during dry spells for the first several years and in extended drought, as the shallow roots dry out quickly. The tree tolerates cold to USDA zone 2 but struggles with summer heat and humidity south of its range. Spruce spider mites, budworms, and the white pine weevil attack the leader and foliage, and needle-cast fungi occur in damp conditions. Trees on exposed sites are subject to windthrow because of the shallow root plate. Established trees need little routine care.Pruning
Little pruning is needed, as the tree forms an even, spire-like crown on its own. Remove dead, damaged, or competing leader shoots in late winter to keep a single straight trunk. Old bare wood does not resprout, so trimming stays within needled growth.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter