
Alnus firma
Alnus firma
Safety & Hazards
None known
Cultivation Details
Prefers a heavy soil and a damp situation[1, 2]. Grows well in heavy clay soils[2]. Tolerates very infertile sites[3]. This species grows on poor, dry, sandy and gravelly soils[4]. 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[5, 3].
Propagation
Seed - best sown in a cold frame as soon as it is ripe and only just covered[3]. Spring sown seed should also germinate successfully so long as it is not covered[3, 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. If you have sufficient quantity of seed, it can be sown thinly in an outdoor seed bed in the spring[6]. 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+firma>
Pollinators
Wind
References
- [1]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 Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [2]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.
- [3]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.
- [4]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.
- [5]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.
- [6]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.
- [7]Flora of Japan. (English translation) — Ohwi. G. · Smithsonian Institution · 1965 · ISBN - ↩︎The standard work. Brilliant, but not for the casual reader.
- [PFAF]Plants for a Future — pfaf.org ↩︎