Like firs (Abies), spruces are pyramidal, with branches arranged in neat tiers. Unlike firs, however, they have pendent cones, 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 that lose their lower branches fairly early in life as they head upward; their canopies thin out noticeably as they age.
Many species have dwarf varieties useful for foundation plantings, in rock gardens, in containers; these plants have shallow root systems and so need a reasonably cool location. Spruces generally grow best where summers are cool or mild; they will not thrive in heat and humidity. Spruces have no special soil requirements.
Birds are attracted to these trees—both for seeds and for shelter. 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.
Native to Rocky Mountain region. In gardens, reaches 30–60 ft. tall, 10–20 ft.wide; in the wild, grows to a possible 100 ft. tall, 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 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.
An emerging category, the intersectional hybrids combine the best traits of herbaceous (P. lactifl...
Native to Europe. Plants grow 1 to 3 ft. tall. Nodding flowers to 2 in. across; short, knobby spurs ab...
Native to eastern and central North America. To 9 ft. tall and 10 ft. wide, with leaves to 3 in. long....