Blue Spruce, Colorado Spruce
Picea pungens
Family: Pinaceae
What it is like
Bloom Color: Green, Orange, Purple. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Columnar, Pyramidal.
Picea pungens is an evergreen Tree growing to 20 m (65ft) by 5 m (16ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 3. It is in leaf all year, and the seeds ripen from September to October. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and is pollinated by Wind. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and can grow in nutritionally poor soil. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It cannot grow in the shade. It prefers dry or moist soil. The plant can tolerates strong winds but not maritime exposure. It cannot tolerate atmospheric pollution.
Height (m): 20
Where it is found
Banks of streams or on first benches above them, singly or in small groves, 2000 - 3300 metres.
South-western N. America - Rocky Mountains.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 2
Young male catkins - raw or cooked. Used as a flavouring. Immature female cones - cooked. The central portion, when roasted, is sweet and syrupy. The cones are about 7cm long. Inner bark - dried, ground into a powder and then used as a thickener in soups etc or added to cereals when making bread. An emergency food, it is only used when all else fails. Seed - raw. The seed is about 2 - 4mm long. It is rich in fats and has a pleasant slightly resinous flavour but is too small and fiddly to be worthwhile unless you are desperate. A refreshing tea, rich in vitamin C, can be made from the young shoot tips.
Inner bark: the bark that is found just beneath the tough outer bark of trees and shrubs.
Seed: includes nuts, cereals, peas and beans.
Tea: the various herb teas that can be used in place of tea, plus the genuine article.
Medicine
Rating: 0
Vitamin C: Plants good for their vitamin C content
Other
Rating: 3
A fairly wind resistant tree, it can be grown as part of a shelterbelt planting. Wood - light, soft, close grained, weak, brittle and often full of knots. The wood has little commercial value, but is used for construction and is also valued for its use in the pulp industry to make paper.
Shelterbelt: Wind resistant plants than can be grown to provide shelter in the garden etc.
Wood: A list of the trees and shrubs that are noted for having useful wood.
Scented Plants: Plants noted for their scent
How it is grown
Landscape Uses:Christmas tree, Firewood, Screen, Specimen. Likes abundant moisture at the roots, if grown in drier areas it must be given a deep moist soil. Tolerates poor peaty soils. Prefers a cold dry high mountain site. Succeeds in wet cold and shallow soils but is not very wind-firm in shallow soils. Resists wind exposure to some degree. This species has a deeply penetrating root system that firmly anchors the tree against winds. Prefers a pH between 4 to 6. Dislikes shade. Intolerant of atmospheric pollution. A long-lived but slow-growing tree in the wild, with specimens 800 years old recorded. It is planted as a timber tree in N. and C. Europe. Most trees in Britain are grafted and these are slow growing. The few trees of seedling origin tend to be fairly fast growing after a slow start. Annual increases of 30 - 40cm are not uncommon in some of the larger trees. Trees should be planted into their permanent positions when they are quite small, between 30 and 90cm. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance. Seed production is usually good, with heavy crops every 2 - 3 years. In some upland areas, especially over granitic or other base-poor soils, growth rate and health have been seriously affected by aluminium poisoning induced by acid rain. Plants are strongly outbreeding, self-fertilized seed usually grows poorly. They hybridize freely with other members of this genus. There are several named forms, selected for their ornamental value. Trees are very subject to severe damage by aphids in mild winter areas where temperatures do not regularly fall below -8°c. All parts of the plant emit a powerful pungent smell when bruised. Special Features:Attracts birds, Attractive foliage, North American native, Inconspicuous flowers or blooms.
Propagating it: Seed - stratification will probably improve germination so sow fresh seed in the autumn in a cold frame if possible. Sow stored seed as early in the year as possible in a cold frame. A position in light shade is probably best. Seed should not be allowed to dry out and should be stored in a cool place. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for their first winter. They can be planted out into their permanent positions in early summer of the following year, or be placed in an outdoor nursery bed for a year or so to increase in size. They might need protection from spring frosts. Cuttings of semi-ripe terminal shoots, 5 - 8cm long, August in a frame. Protect from frost. Forms roots in the spring. Cuttings of mature terminal shoots, 5 - 10cm long, September/October in a cold frame. Takes 12 months. Cuttings of soft to semi-ripe wood, early summer in a frame. Slow but sure.
Best place to grow: Woodland Garden Canopy;
Habit: Tree
Hardiness: 3-7
Growth: Medium
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Dry, moist