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.
'Conica' is a dense, cone-shaped, semi-dwarf to dwarf shrub form with soft bright green foliage. It matures over a number of years to 10-13' tall. Growth rate is 2-4" per year. Needles (to 1/2" long) are aromatic when crushed. Cones are rarely produced. Sharp pointed tip will broaden with age. 'Conica' was discovered by J. G. Jack and Alfred Rehder at Lake Laggan, Alberta, Canada, in 1904. Plants are often trimmed into topiary forms when grown in containers.
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
'Conica' is commonly planted (some say overplanted) as a pyramidal evergreen shrub. Foundations. Landscape accent. Screen. Excellent container plant which can be creatively trimmed into spirals, pom-poms or poodle-cuts.