Common Name: Sitka Alder

General Information

Alnus alnobetula is a spreading to compact, deciduous shrub or small tree that can grow up to 10 metres tall but is more likely to be within the range 1 - 3 metres[, ].
The tree is harvested from the wild for local use as a medicine, source of materials and possibly also as a food. It is a pioneer species and can be used for restoring native woodland.

Known Hazards

The freshly harvested inner bark is emetic but is alright once it has been dried[].

Botanical References

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Range

Widespread through temperate and subarctic regions of Europe, Asia and N. America.

Habitat

Moist woods, stream banks, margins of ponds, to open but moist montane slopes at or near the timber line[]. Along streams, lakeshores, coasts, and bog or muskeg margins, or on sandy or gravelly slopes or flats, from sea level to 2,000 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	4.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Grows best in a sunny position[]. Prefers a heavy soil and a damp situation[, ]. Grows well in heavy clay soils[]. Tolerates very infertile sites[].
A fast-growing but short-lived species, rarely living longer than 50 years[]. It is a pioneer species of logged or burnt land, often forming dense thickets in low wet areas[].
The plant coppices easily, regrowing from the stump and also from suckers[].
This species has a symbiotic relationship with certain soil micro-organisms, these form nodules on the roots of the plants and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Catkins - raw or cooked. A bitter flavour[].

Medicinal

The bark is astringent, emetic, haemostatic, stomachic and tonic[]. The bark was burnt as an inhalant in the treatment of rheumatism[]. The ashes were also used as a tooth cleaner[].
A decoction of the inner bark has been used as a carminative to reduce gas in the stomach and as a febrifuge[].
A decoction of the plant has been used in a steam treatment to bring about menstruation - it has been used as an abortifacient[].

A poultice of the leaves has been used to treat infected wounds or sores[]. The poultice was left in place over the wound until the leaves stuck to it and was then pulled off, removing the 'poison' with it[].

An infusion of the plant tops was given to children with poor appetites[].

Agroforestry Uses:

This is one of the first successional taxa to appear in the northwestern mountains of N. America following disruption of the mature vegetation. It often forms dense thickets on avalanche and talus slopes[]. It is an excellent pioneer species for re-establishing woodlands on disused farmland, difficult sites etc[]. Its fast rate of growth means that it quickly provides sheltered conditions to allow more permanent woodland trees to become established. In addition, bacteria on the roots fix atmospheric nitrogen - whilst this enables the tree to grow well in quite poor soils it also makes some of this nitrogen available to other plants growing nearby. Alder trees also have a heavy leaf canopy and when the leaves fall in the autumn they help to build up the humus content of the soil. Alder seedlings do not compete well in shady woodland conditions and so this species gradually dies out as the other trees become established[].
The tree has an extensive root system and can be planted to control banks from erosion[, ].

Other Uses

The bark and the strobils are a source of tannin[].

An orange-red to brown dye can be obtained from the bark[].

The wood is soft, straight-grained, very durable in water[]. The tree is too small to be of use as a source of lumber, but the wood is used locally for fuel[, ].

Propagation

Seed - best sown in a cold frame as soon as it is ripe and only just covered[]. Spring sown seed should also germinate successfully so long as it is not covered[, ]. The seed should germinate in the spring as the weather warms up. When large enough to handle, prick the seedlings out into individual pots. If growth is sufficient, it is possible to plant them out into their permanent positions in the summer, otherwise keep them in pots outdoors and plant them out in the spring.
If you have sufficient quantity of seed, it can be sown thinly in an outdoor seed bed in the spring[]. The seedlings can either be planted out into their permanent positions in the autumn/winter, or they can be allowed to grow on in the seed bed for a further season before planting them.
Cuttings of mature wood, taken as soon as the leaves fall in autumn, outdoors in sandy soil.