Family: Pinaceae
Common Name: Spruce

There are around 40 species of evergreen conifers in this genus from mountainous regions of the northern hemisphere. Widely cultivated for their lovely form and evergreen foliage, they are distinguishable from other members of Pinaceae by their short, needle-like leaves which are arranged spirally on the branches, and vary from bright green to blueish in colour. Unlike firs (Abies), which they most closely resemble, they have pendulous cones. Fast-growing to a conical or columnar shape, spruces make handsome ornamentals for cooler climates. There are a number of attractive dwarf cultivars, suitable for smaller gardens. Several species yield excellent timber.

Species

P. abies, common or Norway spruce, zone 3, is native to Northern and Central Europe, where it can reach 60 m (200 ft) tall. In cultivation, it usually grows to about 20 m (65 ft). It has a very straight trunk, with a long, narrow, central leader, downward-sweeping, irregularly spaced side branches and pendulous hranchlets. Popular dwarf cultivars are 'Clanbrassiliana', which grows to 1.5 m (5 ft) and has short leaves; 'Globosa Nana', with a very tight, compact habit, to 80 cm (32 in) high; and 'Nidiformis', which is a flat-topped shrub, to about 1 m (3 ft) high, with short leaves.

P. glauca, white spruce, zone 3, from Canada, grows to 30 m (100 ft) when mature, but grows rather slowly. In the US, the superb dwarf cultivar, var. albertiana 'Corsica', is better known. It grows up to 1 m (3 ft) high in a perfect cone shape.

P. omorika, Serbian spruce, zone 4, from Serbia and Bosnia, has a very narrow, upright growth habit, deep blueish green foliage and pendulous branches. This striking tree can reach 20 m (65 ft) in cultivation.

P. pungens, Colourado or blue spruce, zone 3, from the west coast mountains of North America, forms a pyramidal shape, growing to around 30 m (100 ft) in the wild. It has blueish green, pointed needles and gray bark. Cultivar 'Glauca', known as blue spruce, is more often grown. It is a conical, symmetrical tree, 7-10 m (23-33 ft) tall, with stiff, spreading, crowded branches. It prefers a cool climate and a dry atmosphere. 'Koster' is another attractive, blue cultivar.

P. smithiana, Himalayan spruce, zone 7, from the western Himalayas, is a vigorous species with a conical habit and graceful, pendulous branches.

Cultivation

Spruces need good rain all year round, cool winters, and deep, fertile soil. Propagation is generally from seed, which germinates easily. The dwarf cultivars must be propagated from cuttings to maintain their characteristic shape and foliage. Some forms of blue spruce are propagated by grafting.

Climate

Cool to cold.