Back to main Search Page

Alnus glutinosa - (L.)Gaertn.

Alder

Author	(L.)Gaertn.	Botanical references	11, 17, 200
Family	Betulaceae	Genus	Alnus
Synonyms	Alnus rotundifolia - Stokes. Betula glutinosa - L.
Known Hazards	None known
Range	Most of Europe, including Britain, to Siberia, W. Asia and N. Africa.
Habitat	Wet ground in woods, near lakes and along the sides of streams, often formng pure woods n succession to marsh or fen[9].
Edibility Rating	0 (1-5)	Medicinal Rating	3 (1-5)

Physical Characteristics

A decidious Tree growing to 25m by 10m at a fast rate.

The plant prefers medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. The plant prefers acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It requires moist or wet soil. The plant can tolerate maritime exposure.

Habitats

Woodland Garden; Canopy; Hedge; Bog Garden;

Edible Uses

None known

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Alterative; Astringent; Cathartic; Emetic; Febrifuge; Galactogogue; Haemostatic; Parasiticide; Skin; Tonic; Vermifuge.

The bark is alterative, astringent, cathartic, febrifuge and tonic[4, 7, 14, 46, 269]. The fresh bark will cause vomiting, so use dried bark for all but emetic purposes[21]. A decoction of the dried bark is used to bathe swellings and inflammations, especially of the mouth and throat[4, 9, 21, 254]. The powdered bark and the leaves have been used as an internal astringent and tonic, whilst the bark has also been used as an internal and external haemostatic against haemorrhage[21]. The dried bark of young twigs are used, or the inner bark of branches 2 - 3 years old[9]. It is harvested in the spring and dried for later use[9]. Boiling the inner bark in vinegar produces a useful wash to treat lice and a range of skin problems such as scabies and scabs[21]. The liquid can also be used as a toothwash[21]. The leaves are astringent, galactogogue and vermifuge[7]. They are used to help reduce breast engorgement in nursing mothers[254]. A decoction of the leaves is used in folk remedies for treating cancer of the breast, duodenum, oesophagus, face, pylorus, pancreas, rectum, throat, tongue, and uterus[269]. The leaves are harvested in the summer and used fresh[238].

Other Uses

Charcoal; Dye; Hedge; Ink; Insecticide; Pioneer; Shelterbelt; Soil reclamation; Tannin; Teeth; Wood.

Tolerant of clipping and maritime exposure, the alder can be grown in a windbreak or a hedge[75]. The trees are very quick to establish[200] and will grow at a rate of 1 metre or more per year when young[K]. This 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[K]. Because they tolerate very poor soils and also produce nitrogen nodules on their roots, alders are suitable for use in land reclamation schemes. The plants can be used as a source of biomass[269]. According to the phytomass files, annual productivity is estimated at 6 to 9 tonnes per hectare. The tree has yielded 11.8 tonnes per hectare per annum on pulverized fuel ash and annual productivity has been estimated at 8.66 tonnes per hectare, with 5.87 tonnes in wood, bark, and branches, 2.79 tonnes in foliage[269]. Alder has been recommended for consideration for firewood plantations in Tropical highlands where unseasonable cold might destroy the red alder[269]. The powdered bark has been used as an ingredient of toothpastes[9]. Sticks of the bark have been chewed as tooth cleaners[9]. An ink and a tawny-red dye are obtained from the bark[4, 6, 7, 66]. A green dye is obtained from the catkins[4, 6, 66]. A pinkish-fawn dye is obtained from the fresh green wood[4, 6, 66]. A yellow dye is obtained from the bark and young shoots[4, 6, 66]. A cinnamon dye is obtained from the shoots if they are harvested in March[4]. If they are dried and powdered then the colour will be a tawny shade[4]. The bark and the fruits contain up to 20% tannin[46, 61, 223], but they also contain so much dyestuff (imparting a dark red shade) that this limits their usefulness[4, 7]. The leaves are also a good source of tannin[4]. The leaves are clammy and, if spread in a room, are said to catch fleas and flies on their glutinous surface[4, 7]. Wood - very durable in water, elastic, soft, fairly light, easily worked, easily split. It is often used for situations where it has to remain underwater and is also used for furniture, pencils, bowls, woodcuts, clogs etc. It is much valued by cabinet makers[4, 7, 11, 13, 26, 46, 66, 100, 115]. The wood also makes a good charcoal[4, 115].

Cultivation details

Prefers a heavy soil and a damp situation[1, 11], tolerating prolonged submergence of its roots and periods with standing water to 30cm deep[186, 200]. 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[24, 98], they also tolerate lime and very infertile sites[200]. Tolerates a wide range of soils but prefers a pH above 6[186]. Very tolerant of maritime exposure[49, 75, 166]. Alder is estimated to tolerate an annual precipitation of 40 to 200cm, an annual average temperature of 8 to 14°C and a pH of 6 to 8[269]. The leaves often remain green on the tree until November, 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[186]. This enables distribution of the seed by water. The alder has a very rapid early growth[98], specimens 5 years old from seed were 4 metres tall even though growing in a very windy site in Cornwall[K]. 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[98, 200]. 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.[269]. Trees often produce adventitious roots from near the base of the stem and these give additional support in unstable soils[186]. Trees are very tolerant of cutting and were at one time much coppiced for their wood which had a variety of uses[4, 186]. Alders are an important food plant for the caterpillars of many butterfly and moth species[30] and also for small birds in winter[24].There are 90 insect species associated with this tree[24]. There are some named varieties, selected for their ornamental value[200]

Propagation

Seed - best sown in a cold frame as soon as it is ripe and only just covered[200]. Spring sown seed should also germinate successfully so long as it is not covered[200, K]. 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[269]. Seeds can remain viable for at least 12 months after floating in water[269]. 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[269]. If you have sufficient quantity of seed, it can be sown thinly in an outdoor seed bed in the spring[78]. 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.

Cultivars

There are many named forms for this species, but these have been developed for their ornamental value and not for their other uses. Unless you particularly require the special characteristics of any of these cultivars, we would generally recommend that you grow the natural species for its useful properties. We have, therefore, not listed the cultivars in this database[K].

Links

This plant is also mentioned in the following PFAF articles: Hedges and their uses.

References

[K] Ken Fern
Notes from observations, tasting etc at Plants For A Future and on field trips.

[1] F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaces in 1992 by a new dictionary (see [200]).

[4] Grieve. A Modern Herbal. Penguin 1984 ISBN 0-14-046-440-9
Not so modern (1930's?) but lots of information, mainly temperate plants.

[6] Mabey. R. Plants with a Purpose. Fontana 1979 ISBN 0-00-635555-2
Details on some of the useful wild plants of Britain. Poor on pictures but otherwise very good.

[7] Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984 ISBN 0-356-10541-5
Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.

[9] Launert. E. Edible and Medicinal Plants. Hamlyn 1981 ISBN 0-600-37216-2
Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.

[11] Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981
A classic with a wealth of information on the plants, but poor on pictures.

[13] Triska. Dr. Hamlyn Encyclopaedia of Plants. Hamlyn 1975 ISBN 0-600-33545-3
Very interesting reading, giving some details of plant uses and quite a lot of folk-lore.

[14] Holtom. J. and Hylton. W. Complete Guide to Herbs. Rodale Press 1979 ISBN 0-87857-262-7
A good herbal.

[17] Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962
A very comprehensive flora, the standard reference book but it has no pictures.

[21] Lust. J. The Herb Book. Bantam books 1983 ISBN 0-553-23827-2
Lots of information tightly crammed into a fairly small book.

[24] Baines. C. Making a Wildlife Garden. 0
Fairly good with lots of ideas about creating wildlife areas in the garden.

[26] Hills. L. Comfrey Report. Henry Doubleday Research Ass. 0
A small booklet giving a fairly comprehensive guide to the uses of comfrey.

[30] Carter D. Butterflies and Moths in Britain and Europe. Pan 1982 ISBN 0-330-26642-x
An excellent book on Lepidoptera, it also lists their favourite food plants.

[46] Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959
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.

[49] Arnold-Forster. Shrubs for the Milder Counties. 0
Trees and shrubs that grow well in Cornwall and other mild areas of Britain. Fairly good, a standard reference book.

[61] Usher. G. A Dictionary of Plants Used by Man. 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.

[66] Freethy. R. From Agar to Zenery. The Crowood Press 1985 ISBN 0-946284-51-2
Very readable, giving details on plant uses based on the authors own experiences.

[75] Rosewarne experimental horticultural station. Shelter Trees and Hedges. Ministry of Agriculture, Fisheries and Food 1984
A small booklet packed with information on trees and shrubs for hedging and shelterbelts in exposed maritime areas.

[78] Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948
A bit dated but a good book on propagation techniques with specific details for a wide range of plants.

[98] Gordon. A. G. and Rowe. D. C. f. Seed Manual for Ornamental Trees and Shrubs. 0
Very comprehensive guide to growing trees and shrubs from seed. Not for the casual reader.

[100] Polunin. O. Flowers of Europe - A Field Guide. 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.

[115] Johnson. C. P. The Useful Plants of Great Britain. 0
Written about a hundred years ago, but still a very good guide to the useful plants of Britain.

[166] Taylor. J. The Milder Garden. Dent 1990
A good book on plants that you didn't know could be grown outdoors in Britain.

[186] Beckett. G. and K. Planting Native Trees and Shrubs. Jarrold 1979
An excellent guide to native British trees and shrubs with lots of details about the plants.

[200] Huxley. A. The New RHS Dictionary of Gardening. 1992. 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.

[223] Rottsieper. E.H.W. Vegetable Tannins The Forestal Land, Timber and Railways Co. Ltd. 1946
A fairly detailed treatise on the major sources of vegetable tannins.

[238] Bown. D. Encyclopaedia of Herbs and their Uses. 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.

[254] Chevallier. A. The Encyclopedia of Medicinal Plants 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.

[269] Duke. J. Handbook of Energy Crops - 1983
Published only on the Internet, excellent information on a wide range of plants.

Readers Comments

Plants for a Future does not verify the accuracy of reader comments, use at your own risk. In particular Plants For A Future can not take any responsibility for any adverse effects from the use of plants. You should always consult a professional before using plants medicinally.

Alnus glutinosa

Greg Nelson Thu Jun 14 2007

Several sources suggest that alder can be tapped to make syrup. Not sure if this applies to this particular species.

Alnus glutinosa

Ricardo Calmet Sat Mar 15 2008

Hello, I am Ricardo Calmet form Ecotintes, Peru. We need buy Alnus glutinosa powder. If is organic better.

Ecotintes

Alnus glutinosa

Marinella Zepigi Tue Jun 10 2008

Acta plantarum forum botanico Alnus glutinosa (L.) Gaertner

Alnus glutinosa

Michael Bell Thu Jun 26 2008

In your discussion of alders you say "hardy to zone 5" (or zone2 or 6) but you don't say anywhere that I can find what these zones are.

Add a comment/link:

Discussion Monitor

To have posts to this page mailed to you enter your email address here:

(Your email address will not appear on the webpage or be passed on to third parties).