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Alnus incana - (L.)Moench.
Common Name Grey Alder, Speckled alder, Thinleaf alder, White Alder
Family Betulaceae
USDA hardiness 2-6
Known Hazards None known
Habitats Mountains, especially on poor soil[17, 50].
Range Europe. Introduced in Britain[17].
Edibility Rating  
Other Uses  
Weed Potential No
Medicinal Rating  
Fully Hardy Well drained soil Moist Soil Wet Soil Semi-shade Full sun

Bloom Color: Purple, Red. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Pyramidal.

Alnus incana Grey Alder, Speckled alder, Thinleaf alder, White Alder

Alnus incana Grey Alder, Speckled alder, Thinleaf alder, White Alder
Physical Characteristics
 icon of manicon of lolypop
Alnus incana is a deciduous Tree growing to 18 m (59ft) by 5 m (16ft) at a fast rate.
It is hardy to zone (UK) 2. It is in flower from Feb to March. The flowers are monoecious (individual flowers are either male or female, but both sexes can be found on the same plant) and are pollinated by Wind.It can fix Nitrogen.
Suitable for: medium (loamy) and heavy (clay) soils and can grow in heavy clay and nutritionally poor soils. Suitable pH: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers dry moist or wet soil. The plant can tolerate maritime exposure.

Betula alnus incana.

Woodland Garden Canopy; 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.

None known
Other Uses
Pioneer;  Soil reclamation;  Tannin;  Wood.

This species fixes atmospheric nitrogen and is also tolerant of polluted soils, it can be used for land reclamation, especially on coal tips[200]. 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]. The bark and the fruits contain up to 20% tannin[46, 61, 223]. Wood - light, soft, fairly elastic, easy to split. Used for clogs, bowls, woodcuts etc. Much valued by cabinet makers[46, 61].
Cultivation details
Landscape Uses:Pollard, Specimen. Prefers a heavy soil and a damp situation[1, 11]. Grows well in heavy clay soils[11]. Thrives in drier soils than many other members of this genus[200]. Tolerates very infertile sites[200]. 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[200]. Special Features:Attractive foliage, Not North American native, Wetlands plant, Inconspicuous flowers or blooms.
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. 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.
Other Names
Found In
Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status
IUCN Red List of Threatened Plants Status :
Related Plants
Latin NameCommon NameEdibility RatingMedicinal Rating
Alnus cordataItalian Alder00
Alnus glutinosaAlder, European alder , Common Alder, Black Alder03
Alnus hirsuta 00
Alnus japonicaJapanese Alder01
Alnus maritimaSeaside Alder, Beach Alder00
Alnus maximowiczii 00
Alnus nepalensisNepalese Alder01
Alnus nitida 01
Alnus rhombifoliaWhite Alder12
Alnus rubraRed Alder, Oregon Alder22
Alnus rugosaSpeckled Alder02
Alnus serrulataSmooth Alder, Hazel alder02
Alnus sinuataSitka Alder11
Alnus tenuifoliaMountain Alder, Thinleaf alder12
Alnus viridis crispaAmerican Green Alder12
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Expert comment
Botanical References
Links / References
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Readers comment
Elizabeth H.
Marinella Zepigi Tue Jun 10 2008

Acta plantarum forum botanico Alnus incana (L.) Moench - Description - Photos

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Subject : Alnus incana  

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