PlantPeers
Back to Catalog
No image available
Betulaceae FAMILY Least Concern

Alnus glutinosa

Alnus glutinosa

Edibility
0/5
Medicinal
3/5

Safety & Hazards

None known

Cultivation Details

HabitDeciduous Tree
GrowthFast

Alnus glutinosa favours a moderate to cold climate and prefers damp or wet soils. It is estimated to tolerate an annual precipitation of 400 - 2,000mm, an annual average temperature of 8 - 14°c[1]. Prefers a heavy soil and a damp situation[2, 3], tolerating prolonged submergence of its roots and periods with standing water to 30cm deep[4, 5]. Plants can also grow quickly in much drier sites, though they will usually not live for so long in such a position. Alders grow well in heavy clay soils[6, 7], they also tolerate lime and very infertile sites[5]. Tolerates a wide range of soils but prefers a pH above 6[4]. Very tolerant of maritime exposure[8, 9, 10]. Prefers a pH n the range 6 - 8[1]. The leaves often remain green on the tree until late autumn, or even later on young seedlings. The seeds contain a margin of air-filled tissue and are capable of floating in water for 30 days before becoming waterlogged[4]. This enables distribution of the seed by water. The alder has a very rapid early growth[7], specimens 5 years old from seed were 4 metres tall even though growing in a very windy site in Cornwall[PFAF]. 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[7, 5]. Nitrogen-fixation by trees up to 8 years old has been put at 125 kg/ha/yr., for 20 years at 56 - 130 kg/ha/yr.[1]. Trees often produce adventitious roots from near the base of the stem and these give additional support in unstable soils[4]. Trees are very tolerant of cutting and were at one time much coppiced for their wood which had a variety of uses[11, 4]. Alders are an important food plant for the caterpillars of many butterfly and moth species[12] and also for small birds in winter[6].There are 90 insect species associated with this tree[6]. The cones open gradually and release seed throughout the winter, they are a dependable source of food for seed-eating birds such as pine siskins and goldfinches[13]. There are some named varieties, selected for their ornamental value[5]

Propagation

Seed - best sown in a cold frame as soon as it is ripe and only just covered[5]. Spring sown seed should also germinate successfully so long as it is not covered[5, PFAF]. 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. There are about 700,000 - 750,000 seeds per kilo, but on average only about 20 - 25,000 plantable seedlings are produced[1]. Seeds can remain viable for at least 12 months after floating in water[1]. Seeds germinate as well under continuous darkness as with normal day lengths. Air-dried seeds stored at 1 - 2°C retained their viability for two years. Seeds can however be sown immediately as soon as ripe[1]. If you have sufficient quantity of seed, it can be sown thinly in an outdoor seed bed in the spring[14]. 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. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Alnus+glutinosa>

Pollinators

Wind

References

  1. [1]Handbook of Energy Crops — Duke. J. · - · 1983 · https://hort.purdue.edu/newcrop/duke_energy/dukeindex.html · ISBN - ↩︎Published only on the Internet, excellent information on a wide range of both temperate and tropical plants.
  2. [2]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
  3. [3]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
  4. [4]Planting Native Trees and Shrubs. — Beckett. G. and K. · Jarrold · 1979 · ISBN - ↩︎An excellent guide to native British trees and shrubs with lots of details about the plants.
  5. [5]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  6. [6]Making a Wildlife Garden. — Baines. C. ↩︎Fairly good with lots of ideas about creating wildlife areas in the garden.
  7. [7]Seed Manual for Ornamental Trees and Shrubs. — Gordon. A. G. and Rowe. D. C. F. · HMSO; London · 1982 · ISBN 0-11-710152-4 ↩︎Very comprehensive guide to growing trees and shrubs from seed. Not for the casual reader.
  8. [8]Shrubs for the Milder Counties. — Arnold-Forster. ↩︎Trees and shrubs that grow well in Cornwall and other mild areas of Britain. Fairly good, a standard reference book.
  9. [9]Shelter Trees and Hedges. — Rosewarne experimental horticultural station. · Ministry of Agriculture, Fisheries and Food · 1984 · ISBN - ↩︎A small booklet packed with information on trees and shrubs for hedging and shelterbelts in exposed maritime areas.
  10. [10]The Milder Garden. — Taylor. J. · Dent · 1990 ↩︎A good book on plants that you didn't know could be grown outdoors in Britain.
  11. [11]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  12. [12]Butterflies and Moths in Britain and Europe. — Carter D. · Pan · 1982 · ISBN 0-330-26642-x ↩︎An excellent book on Lepidoptera, it also lists their favourite food plants.
  13. [13]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  14. [14]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
  15. [15]Flora of the USSR. — Komarov. V. L. · Israel Program for Scientific Translation · 1968 · http://www.biodiversitylibrary.org · ISBN - ↩︎An immense (25 or more large volumes) and not yet completed translation of the Russian flora. Full of information on plant uses and habitats but heavy going for casual readers. It can be downloaded from the Internet.
  16. [16]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
  17. [17]Edible and Medicinal Plants. — Launert. E. · Hamlyn · 1981 · ISBN 0-600-37216-2 ↩︎Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
  18. [18]Encyclopaedia of Medicinal Plants. — Chiej. R. · MacDonald · 1984 · ISBN 0-356-10541-5 ↩︎Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.
  19. [19]Complete Guide to Herbs. — Holtom. J. and Hylton. W. · Rodale Press · 1979 · ISBN 0-87857-262-7 ↩︎A good herbal.
  20. [20]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  21. [21]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  22. [22]The Encyclopedia of Medicinal Plants — Chevallier. A. · Dorling Kindersley. London · 1996 · ISBN 9-780751-303148 ↩︎An excellent guide to over 500 of the more well known medicinal herbs from around the world.
  23. [23]Encyclopaedia of Herbs and their Uses. — Bown. D. · Dorling Kindersley, London. · 1995 · ISBN 0-7513-020-31 ↩︎A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
  24. [24]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
  25. [25]Vegetable Tannins — Rottsieper. E.H.W. · The Forestal Land, Timber and Railways Co. Ltd. · 1946 · ISBN - ↩︎A fairly detailed treatise on the major sources of vegetable tannins.
  26. [26]Plants with a Purpose. — Mabey. R. · Fontana · 1979 · ISBN 0-00-635555-2 ↩︎Details on some of the useful wild plants of Britain. Poor on pictures but otherwise very good.
  27. [27]From Agar to Zenery. — Freethy. R. · The Crowood Press · 1985 · ISBN 0-946284-51-2 ↩︎Very readable, giving details on plant uses based on the authors own experiences.
  28. [28]Hamlyn Encyclopaedia of Plants. — Triska. Dr. · Hamlyn · 1975 · ISBN 0-600-33545-3 ↩︎Very interesting reading, giving some details of plant uses and quite a lot of folk-lore.
  29. [29]Comfrey Report. — Hills. L. · Henry Doubleday Research Ass. ↩︎A small booklet giving a fairly comprehensive guide to the uses of comfrey.
  30. [30]Flowers of Europe - A Field Guide. — Polunin. O. · Oxford University Press · 1969 · ISBN 0192176218 ↩︎An excellent and well illustrated pocket guide for those with very large pockets. Also gives some details on plant uses.
  31. [31]The Useful Plants of Great Britain. — Johnson. C. P. ↩︎Written about a hundred years ago, but still a very good guide to the useful plants of Britain.
  32. [PFAF]Plants for a Future — pfaf.org ↩︎