Culture
Best grown in moist, well-drained soils in full sun. Tolerates some light shade. Best performance is in cold winter climates with cool summers. Site in areas with good air circulation to help rid the dense foliage of moisture. Somewhat intolerant of urban stresses such as air pollutants and salt spray. Plants will struggle in the high heat and humidity of St. Louis summers, and should not be grown in the eastern U.S. south of USDA Zone 6.
Noteworthy Characteristics
Picea glauca, commonly called white spruce, is an extremely hardy evergreen conifer that is native to upland areas and lake/stream margins stretching from Alaska across the boreal forest of Canada to Newfoundland, dipping south to Montana, Minnesota, Wisconsin, Michigan and New York. This tree typically grows 60-80' tall (less frequently to 140' tall) with a cone-shaped crown. It diminishes in size to low, shrubby forms near tree line in northern Canada. Blue-green needles (to 3/4") on small woody pegs have sharp tips. Needles are pungently aromatic when crushed. Needles have a glaucous (white waxy coating) bloom, hence the specific epithet and common name. Branchlets do not droop. Cylindrical pale brown cones (to 2.5" long) have flexible scales.
Genus name is reportedly derived from the Latin word pix meaning "pitch" in reference to the sticky resin typically found in spruce bark.
Specific epithet both are in reference to the fact that mature needles of this tree become glaucous (acquire a waxy white bloom) with age.
'Densata, commonly called Black Hills spruce, is a variety of white spruce that is native to a geographically isolated area in and around the Black Hills of South Dakota. It was originally called Picea glauca var. densata, but many experts now designate it as Picea glauca ‘Densata’ because its differences from the species are judged insufficient to justify classification as a botanical variety. In its small native habitat, it is commonly found growing at around 6000’ in elevation. It typically grows rather slowly in a dense, symmetrical cone to 20-25’ tall, but over time may rise to 40-60’ or more. It is distinguished from the species by having (1) smaller size with slower growth rate, (2) denser habit, (3) brighter green to blue-green needles and (4) slightly shorter cones. By reputation in the horticulture industry, Black Hills spruce is a superior ornamental tree to the species. Black Hills spruce is the state tree of South Dakota.
Problems
No serious insect or disease problems. Susceptible to needle and stem rust, canker, trunk and root rot. Yellow-headed spruce sawfly, spruce budworm and eastern spruce beetle are problems in some areas. Mites are common and repeated infestations can do serious injury to the plant. Intolerant of urban stresses (pollution, salt spray).
Uses
Specimen for landscape. Windbreak or screen.