Herb: Alder

Latin name: Alnus glutinosa

Synonyms: Alnus rotundifolia, Betula glutinosa

Family: Betulaceae (Birch Family)

Medicinal use of Alder:

The bark is alterative, astringent, cathartic, febrifuge and tonic. The fresh bark will cause vomiting, so use dried bark for all but emetic purposes. A decoction of the dried bark is used to bathe swellings and inflammations, especially of the mouth and throat. 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. The dried bark of young twigs are used, or the inner bark of branches 2 - 3 years old. It is harvested in the spring and dried for later use. Boiling the inner bark in vinegar produces a useful wash to treat lice and a range of skin problems such as scabies and scabs. The liquid can also be used as a toothwash. The leaves are astringent, galactogogue and vermifuge. They are used to help reduce breast engorgement in nursing mothers. 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. The leaves are harvested in the summer and used fresh.

Description of the plant:


25 m
(82 feet)

to April

Habitat of the herb:

Wet ground in woods, near lakes and along the sides of streams, often formng pure woods n succession to marsh or fen.

Other uses of Alder:

Tolerant of clipping and maritime exposure, the alder can be grown in a windbreak or a hedge. The trees are very quick to establish and will grow at a rate of 1 metre or more per year when young. 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. 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. 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. Alder has been recommended for consideration for firewood plantations in Tropical highlands where unseasonable cold might destroy the red alder. The powdered bark has been used as an ingredient of toothpastes. Sticks of the bark have been chewed as tooth cleaners. An ink and a tawny-red dye are obtained from the bark. A green dye is obtained from the catkins. A pinkish-fawn dye is obtained from the fresh green wood. A yellow dye is obtained from the bark and young shoots. A cinnamon dye is obtained from the shoots if they are harvested in March. If they are dried and powdered then the colour will be a tawny shade. The bark and the fruits contain up to 20% tannin, but they also contain so much dyestuff (imparting a dark red shade) that this limits their usefulness. The leaves are also a good source of tannin. The leaves are clammy and, if spread in a room, are said to catch fleas and flies on their glutinous surface. 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. The wood also makes a good charcoal.

Propagation of the herb:

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. There are about 700,000 - 750,000 seeds per kilo, but on average only about 20 - 25,000 plantable seedlings are produced. Seeds can remain viable for at least 12 months after floating in water. Seeds germinate as well under continuous darkness as with normal day lengths. Air-dried seeds stored at 1 - 2C retained their viability for two years. Seeds can however be sown immediately as soon as ripe. 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.

Cultivation of Alder:

Wet ground in woods, near lakes and along the sides of streams, often formng pure woods n succession to marsh or fen.

Known hazards of Alnus glutinosa:

None known

Plant information taken from the Plants For A Future.