Picea pungens

Picea pungens (30/12/14, Kew Gardens, London)

Position: Full sun 

Flowering period: Spring

Soil: Moist, well drained

Eventual Height: 15m

Eventual Spread: 5m

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b

Family: Pinaceae

Picea pungens is an evergreen conifer tree with a conical habit. Its grey/ green needle like leaves are rigid, arranged singly all round the shoots and up to 3cm long. Its grey/ black bark is scaled. The monoecious flowers are ornamentally inconspicuous. Its fruit are narrow hanging cylindrical cones which are up to 10cm long and borne near the end of its shoots. These emerge a red/ violet, maturing to pale brown.

Picea pungens Leaf (30/12/14, Kew Gardens, London)

Picea pungens, commonly known as the Colorado Blue Spruce, Blue Spruce or Green Spruce is native to west United States. In its native habitat it grows in mountain valleys near streams where moisture levels are high. It is a plant that displays positive phototropism as well as negative gravitropism or geotropism in its stems as it reaches towards the light out of the seed.

The etymological root of the binomial name Picea is derived from the Lain Pix meaning ‘pitch or tar’ in reference to the trees resin. Pungens is derived from the Latin meaning ‘prick, puncture or sting’ in reference to the leaves.

The landscape architect may find Picea pungens useful as an attractive evergreen specimen parkland tree, due to its blue foliage and textured effect. It also makes an effective windbreak or visual screen. It will not tolerate urban pollution.

Ecologically, Picea pungens provides habitat and food for birds.

Picea pungens Bark (30/12/14, Kew Gardens, London)

The Royal Horticultural Societie has awarded a number of varieties of Picea pungens its award of garden merit.

Picea pungens prefers moist humus rich soils. It will tolerate most soil pH although it prefers acid soils and dislikes chalky soils. It will also withstand short periods of drought (unusual for a Spruce).

Picea pungens requires little maintenance.

Picea pungens ‘Koster’

Picea pungens ‘Koster’ (08/10/2011, Horní Bečva, Czech)

Position: Full sun 

Flowering period: May

Soil: Moist 

Eventual Height: 4-15m (Unpredictable)

Eventual Spread: 1.5-4m (Unpredictable)

Hardiness: 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a

Family: Pinaceae

Picea pungens ‘Koster’ is a medium sized evergreen conifer tree with a narrow conical growth habit. It’s glaucous foliage is silvery blue becoming grey-green with age. It’s leaves are rigid, needle like, arranged singly all round the shoots and are 15-30mm long. The monoecious flowers are ornamentally inconspicuous. The tree gives rise to narrow hanging cylindrical cones which are 4-10 cm in length, emerge a reddish to violet colour, maturing to a pale brown. They have leathery scales and are borne near the end of the shoots. The bark of the tree is grayish black, scaled  with glossy orange brown twigs. It’s trunk tapers rapidly.

Picea pungens ‘Koster’, commonly known as the Colorado Blue Spruce, is native to the Western United States. It is a plant that displays positive phototropism as well as negative gravitropism or geotropism in its stems as it reaches towards the light out of the seed. It is found in mountain valleys, but chiefly found near streams where moisture levels are high. Picea pungens was discovered in the Rocky Mountains, USA in  1861, eventually arriving in Europe in the late 19th Century. The variety Picea pungens ‘Koster’ displays a lack of uniformity between plants.

Picea pungens ‘Koster’ (08/10/2011, Horní Bečva, Czech)

The etymological root of the binomial name Picea is derived from the Lain Pix meaning ‘pitch or tar’ in reference to the trees resin. Pungens is derived from the Latin meaning ‘prick, puncture or sting’ in reference to the leaves. 

The landscape architect may find Picea pungens ‘Koster’ useful as an attractive evergreen specimen parkland tree, due to its blue foliage and textured effect. It also make an effective windbreak or visual screen.

Ecologically, Picea pungens ‘Koster’ provides habitat and food for birds.

Picea pungens ‘Koster’ has been awarded the Royal Horticultural Societies award of garden merit in 1993.

Picea pungens ‘Koster’ prefers moist soils as it is commonly found beside streams in it’s native habitat. It will tolerate most soil pH although it prefers acid soils and dislikes chalky soils. It will also withstand short periods of drought (unusual for a Spruce).

Picea pungens ‘Koster’ requires little maintenance.

Landscape Architecture