Practical
Plants

Tsuga heterophylla

Western Hemlock

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Taxonomy and growth

Family
Pinaceae
Genus
Tsuga
Life cycle
perennial
Foliage
evergreen
Woodiness
woody
Growth rate
vigorous
Height
70 m
Spread
15 m
Fertility
Wind
Flower type
monoecious
Pollinators
Wind

Uses

Edible uses

Inner bark - raw or cooked[12][16]. It can be dried, ground into a powder and then used as a thickening in soups etc or mixed with cereals when making bread[4]. It has also been used as a sweetener for other foods[16]. The inner bark was often cooked and then dried for use in the winter[15]. At its best in spring[6], it was one of the staple foods of the Alaskan Indians[24]. An emergency food, it is only used when all else fails[7]. The leaves and twigs yield 'spruce oil', used commercially to flavour chewing gum, soft drinks, ice cream etc[7]. Pitch, obtained from crevices in the bark, has been chewed as a gum[16]. The leaves and young shoots have been chewed as an emergency food to keep one alive when lost in the woods[16]. A herbal tea is made from the leaves and shoot tips[6][7]. These tips are also an ingredient of 'spruce beer'[7].

Product or use
Condiment
Product or use
Gum
Plant part
Inner bark
Product or use
Tea

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

Western hemlock was commonly employed medicinally by several native North American Indian tribes who used it to treat a variety of complaints[16]. It is little, if at all, used in modern herbalism. The bark is astringent, diaphoretic and diuretic[11]. A decoction of the pounded bark has been used in the treatment of haemorrhages, tuberculosis and syphilis[16]. The boiled bark, combined with liquorice fern (Polypodium glyccyrhiza), has been used in the treatment of haemorrhages[16]. An infusion of the inner bark or twigs is helpful in the treatment of kidney or bladder problems[11]. It can also be used as a good enema for treating diarrhoea and as a gargle or mouthwash for mouth and throat problems[11]. Externally, it can be used as a wash on sores and ulcers[11][16]. A poultice of the plant has been applied to bleeding wounds[16]. A moxa of the twigs has been used to get rid of warts[16]. The powdered bark can be put into shoes for tender or sweaty feet or for foot odour[11]. The gum obtained from the trunk has been applied to cuts[16]. It has been applied to the skin to prevent chapping and sunburn[16]. A poultice of the chewed leaves has been used in the treatment of burns[16].

Product or use
Astringent
Product or use
Diaphoretic
Product or use
Diuretic
Product or use
Poultice
Product or use
Skin

Material uses

Yields a resin similar to Abies balsamea, it is gathered by incisions in the trunk or by boiling the wood[17][19][20]. The bark contains 8 - 18% tannin and is a major source of tannin in America[17][24][5][13]. A reddish-brown dye is obtained from the bark[11][17][16]. A decoction of the bark has been used to clean rust off iron and steel[16]. A pitch (called hemlock pitch), is obtained by distillation of the young branches[17]. The pitch is rubbed on the hair to get rid of head lice[16]. Tolerant of light trimming, plants can be grown as a hedge[23]. This species makes a good hedge in Britain[3][9]. Wood - light, hard, tough, easy to work. Commercially superior to other members of this genus, it is an important tree for construction, the outside of buildings etc and for carving into spoons etc[17][19][24][5][13][14]. It is also a major source of pulp[13]. The wood makes a slow-burning fuel and so can be used to bank up a fire to keep it burning overnight[16].

Product or use
Dye
Product or use
Fuel
Product or use
Parasiticide
Product or use
Resin
Product or use
Rust treatments
Product or use
Tannin
Product or use
Wood

Ecology and functions

Ecosystem niche
Canopy

Hedge

Environment

Range
Western N. America - Alaska to N. California.
Habitat
Forests, especially where moist and especially in deep forests[18].
Light
full sun
Shade tolerance
permanent shade
Water
moderate
Hardiness
Zone 6+
Soil textures
sandy, loamy, clay
Soil pH
very acid, acid, neutral, alkaline
Drainage
well drained
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

Seed - it germinates better if given a short cold stratification[22][2] and so is best sown in a cold frame in autumn to late winter. It can also be sown in early spring, though it might not germinate until after the next winter. If there is sufficient seed, an outdoor sowing can be made in spring[21]. Pot-grown seedlings are best potted up into individual pots once they are large enough to handle - grow them on in a cold frame and plant them out in early summer of the following year. Trees transplant well when they are up to 80cm tall, but they are best put in their final positions when they are about 30 - 45 cm or less tall, this is usually when they are about 5 - 8 years old[9]. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance[9].

Cultivation

An easily grown plant, it thrives best when growing in a deep well-drained soil in the western parts of Britain where it appreciates the higher rainfall[1]. However, it succeeds in most soils and positions, being especially good on acidic sandy soils[23] but also tolerating some lime[1] so long as there is plenty of humus in the soil[10]. Plants are very shade tolerant when young, but need more sunlight as they grow older[23][9]. Plants are thin and poor when grown in dry or exposed places[9]. Occasionally cultivated for its timber in Britain, it can grow 60 - 150cm per year[1][8]. New growth takes place from mid-May to mid-September, at first it hangs downwards but begins to straighten towards the end of the season[8]. There are trees more than 50 metres tall in Britain[9]. Trees live for several centuries in the wild and often produce large quantities of seed[14]. Plants often form pure stands and cast a dense shade, thus preventing the regeneration of other trees whilst being able to reproduce itself[13]. Plants in this genus are notably resistant to honey fungus[9].

References

  1. Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00

    ↩1↩2↩3

  2. Dirr. M. A. and Heuser. M. W. The Reference Manual of Woody Plant Propagation. Athens Ga. Varsity Press 1987-00-00 ISBN 0942375009

    ↩

  3. RHS. The Garden. Volume 113. Royal Horticultural Society 1988-00-00

    ↩

  4. Yanovsky. E. Food Plants of the N. American Indians. Publication no. 237. U.S. Depf of Agriculture.

    ↩

  5. Hill. A. F. Economic Botany. The Maple Press 1952-00-00

    ↩1↩2

  6. Schofield. J. J. Discovering Wild Plants - Alaska, W. Canada and the Northwest.

    ↩1↩2

  7. Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9

    ↩1↩2↩3↩4

  8. Mitchell. A. F. Conifers in the British Isles. HMSO 1975-00-00 ISBN 0-11-710012-9

    ↩1↩2

  9. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2↩3↩4↩5↩6↩7

  10. Thomas. G. S. Plants for Ground Cover J. M. Dent & Sons 1990-00-00 ISBN 0-460-12609-1

    ↩

  11. Lust. J. The Herb Book. Bantam books 1983-00-00 ISBN 0-553-23827-2

    ↩1↩2↩3↩4↩5↩6

  12. Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980-00-00 ISBN 0-449-90589-6

    ↩

  13. Lauriault. J. Identification Guide to the Trees of Canada Fitzhenry and Whiteside, Ontario. 1989-00-00 ISBN 0889025649

    ↩1↩2↩3↩4

  14. Elias. T. The Complete Trees of N. America. Field Guide and Natural History. Van Nostrand Reinhold Co. 1980-00-00 ISBN 0442238622

    ↩1↩2

  15. Turner. N. J. Food Plants of Coastal First Peoples UBC Press. Vancouver. 1995-00-00 ISBN 0-7748-0533-1

    ↩

  16. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9

    ↩1↩2↩3↩4↩5↩6↩7↩8↩9↩10↩11↩12↩13↩14↩15↩16↩17

  17. Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959-00-00

    ↩1↩2↩3↩4↩5

  18. Hitchcock. C. L. Vascular Plants of the Pacific Northwest. University of Washington Press 1955-00-00

    ↩

  19. Usher. G. A Dictionary of Plants Used by Man. Constable 1974-00-00 ISBN 0094579202

    ↩1↩2

  20. Howes. F. N. Vegetable Gums and Resins. Faber

    ↩

  21. Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00

    ↩

  22. McMillan-Browse. P. Hardy Woody Plants from Seed. Grower Books 1985-00-00 ISBN 0-901361-21-6

    ↩

  23. Rushforth. K. Conifers. Christopher Helm 1987-00-00 ISBN 0-7470-2801-X

    ↩1↩2↩3

  24. Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. 1965-00-00 ISBN 0-486-20278-X

    ↩1↩2↩3

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