Common Name: White Spruce

General Information

Picea laxa is an evergreen tree that can grow up to 15 metres tall.
This species is a major source of timber in northern N. America, whille the plant has a wide range of traditional uses as a food, medicine and source of materials. It is often grown as an ornamental - several slow-growing dwarf forms have been developed.
Picea laxa is the most widespread spruce in North America. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

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Range

Northern N. America - Alaska to Newfoundland.

Habitat

Woods in good soils[]. Along streams and lakes and also on rocky hills and slopes, succeeding in a variety of soil conditions[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	15.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Picea laxa is a very cold-hardy plant, able to tolerate temperatures down to around -40°c when fully dormant[].
Likes abundant moisture at the roots, if grown in drier areas it must be given a deep moist soil[]. Tolerates poor peaty soils[]. Succeeds in wet cold and shallow soils but is not very wind-firm in shallow soils[]. Prefers a pH between 4 to 6[]. Dislikes shade[]. Intolerant of atmospheric pollution[]. Resists wind exposure to some degree[].
A fast growing tree, especially when young with annual increases of up to 1 metre in height[]. New growth takes place from April to July. Growth slows considerably as the trees grow older[]. It is an important forestry tree in N. America and is also planted for timber in N. Europe. It is sometimes used as a 'Christmas tree', but is unsuited for this because its leaves quickly fall[].
Seed production begins at approximately 20 years, though reliable crops make take twice that long[]. Heavy crops are produced every 2 - 5 years[].
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[].
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 some named varieties selected for their ornamental value[].
The crushed leaves are quite aromatic. Some people find the smell distasteful saying that it is like skunks[], whilst others say it has a pleasant smell like blackcurrants or mouldy grapefruit[].

Edible Uses

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 5cm long[].

Inner bark - raw or cooked[]. It can be dried, ground into a powder and then used as a thickener in soups etc or added to cereals when making bread[]. Usually harvested in the spring[], it is an emergency food that is only used when all else fails.

Seed - raw[]. The seed is about 2 - 4mm long[] and 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[].

The trunk yields a gum, used for chewing[, ].

Spruce oil, distilled from the leaves and twigs, is used in the food industry to flavour chewing gum, ice cream, soft drinks and sweets[].

Medicinal

White spruce was widely employed medicinally by several native North American Indian tribes, who valued it especially for treating chest complaints[]. It is little, if at all, used in modern herbalism.

An infusion of the cones has been used in the treatment of urinary troubles[].

The inner bark is pectoral[]. It has been chewed, and an infusion drunk, in the treatment of TB, influenza, coughs and colds[]. An infusion is also drunk in the treatment of rheumatism[].
The inner bark has also been used as a poultice on sores and infected areas, and has also been used to bandage cuts[].

The tea made from the young shoot tips has antiseptic properties[]. It is used in the treatment of respiratory infections[].
A decoction of the stems is used as a herbal steam bath in the treatment of rheumatism[].

The gum is antiseptic, digestive, laxative, pectoral and salve[]. A decoction has been used in the treatment of respiratory complaints[]. The gum obtained from the trunk (probably pitch[]) has been used as a salve on sores and cuts[]. A poultice of the gum mixed with oil has been used to treat skin rashes, scabies, persistent scabs, growing boils etc, and has also been used on wounds where there is blood poisoning[].

The rotten, dried, finely powdered wood has been used as a baby powder and as a treatment for skin rashes[].

Agroforestry Uses:

A fairly wind resistant tree, it can be grown as part of a shelterbelt planting[]. The cultivar 'Denstat' has been recommended[].

Other Uses

The leaves have been burnt to repel insects[].

Various native North American Indian tribes made a string from the long roots of this species and used it to stitch the bark of their canoes and to make baskets etc[, ].

The rotten, dried, finely powdered wood has been used as a baby powder and as a treatment for skin rashes[].

The bark is a source of tannin[].

A yellow-brown dye can be obtained from the rotten wood[].

The pitch obtained from the trunk can be used as a waterproofing sealant in canoes[].

Wood - straight-grained, resilient, light, soft, not strong. Used for construction and as a source of pulp for paper making[, , , ]. The resonance of the wood, and its capacity to transmit vibrations, make it an ideal wood for guitars, violins, piano soundboards etc[].
Log cabins in Alaska are often built with White Spruce, with the bark left on the outside and moss put between the logs[]. High grade, straight and even-grained timber is used for indoor finishing and flooring, carpentry and joinery[]. Small volume uses are the manufacture of boxes, musical instruments (sounding boards) and canoe paddles[].

Propagation

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/early autumn in a cold frame. Takes 12 months[].
Cuttings of soft to semi-ripe wood, early summer in a frame. Slow but sure.