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.
Native to the Rocky Mountain region. In gardens, reaches 30–60 ft. tall and 10–20 ft. wide; in the wild, grows to a possible 100 ft. tall and 25–35 ft. wide. Very stiff, regular, horizontal branches form a broad pyramid. Foliage of seedlings varies in color from dark green through all shades of blue green to steely blue. Poor choice for the Puget Sound region, where lack of winter cold leads to severe aphid infestations. Throughout its range, subject to an aphid that forms galls. Prefers dry soil.
Plants in the Glauca group (formerly listed as P. p. glauca) are called Colorado blue spruces; they are like the species but with bluish foliage.
Deciduous shrub or tree. Native to eastern North America, this upright grower reaches 15–30 ft. ...
Grows 20 in. tall and wide, with gold and green variegated foliage. You can get selections with blue, ...
Perennials. Well-grown clumps reach 2–4 ft. tall and wide. Large, glossy, deep green, attractive...