Like firs (Abies), spruces are pyramidal trees, with branches arranged in neat tiers. Unlike firs, however, their cones hang down, and their needles are stiffer and attached to branches by small pegs that remain behind after the needles drop. Most spruces are tall timber trees, but dwarf varieties are lovely in home gardens. Plants have shallow root systems and so need a reasonably cool location. Spruces generally grow best where summers are cool or mild; most suffer in heat and humidity. P. pungens tolerates dry conditions better than the other species.
Spruces can be grown in containers for years as living Christmas trees and moved indoors for up to a week. In coldest climates, move potted trees to a protected location for winter.
Check spruces for small, dull green aphids in winter; if they’re present, take control measures at that time to prevent defoliation in spring. Pine needle scale (look for flat, white scale insects on needles) may encourage sooty mold. In Rocky Mountain states, spruces may be bothered by spider mites and tussock moths. Cooley spruce gall adelgid is an aphidlike insect that attacks many spruce trees, especially in the Pacific Northwest and mountain areas. Its feeding causes green, conelike galls to form at ends of new growth. These galls gradually turn light purplish tan and then brown by autumn. Douglas fir is an alternate host for these pests, but it doesn’t develop galls. Contact your local Cooperative Extension Office for control measures.Picea sitchensis
Native to cool, foggy areas from Alaska to California. The largest of all spruces, this is a pyramidal tree 80–160 ft. tall and 20–40 ft. wide in cultivation; plants in the wild may grow much taller. Horizontal branches hold short, flat, prickly needles that are glossy dark green above, powder blue beneath. Needs moisture in both atmosphere and soil to look its best. Subject to Cooley spruce gall. ‘Tenas’ (‘Papoose’) is a dwarf variety, eventually to 4–5 ft. tall and wide.
Native to cool, foggy areas from Alaska to California. The largest of all spruces, this is a pyramidal...
Grows to 3 ft. high and 2 ft. wide. Long-stemmed, toothed medium green leaves are broadly oval with a ...
A delicate woodland groundcover, twinflower forms ground-hugging mats of evergreen, glossy green leave...