{"slug":"alnus-glutinosa","scientific_name":"Alnus glutinosa","common_names":["Alder","Common alder","Black alder"],"family":"Betulaceae","type":"broadleaf_deciduous","mature_height_m":25,"mature_spread_m":10,"growth_rate":"fast","lifespan_years":60,"hardiness_zones":[3,7],"sun":"full","water":"high","soil":"Wet, poorly drained or periodically flooded soils; also grows on drier ground","native_range":"Native across Europe including Britain and Ireland, to North Africa, Türkiye, the Caucasus, Iran and western Siberia.","description":"A conical to rounded tree of around 28 m with sticky young leaves, dark woody cones and roots that fix nitrogen with the bacterium Frankia. It is the tree for riverbanks, ponds and waterlogged corners where little else will grow, stabilising banks and sheltering otters, siskins and redpolls. Widely planted in riparian restoration and flood-mitigation schemes.","care":"Plant in winter straight into damp ground; no staking needed and it tolerates having its feet in water. Prune in late summer if required. The main threat is Phytophthora alder disease (root rot, bleeding bark lesions, small yellow leaves); avoid moving soil or plants from affected sites. Roughly 60-year lifespan.","benefits":["nitrogen_fixing","erosion_control","flood_tolerant","wildlife","birds","fast_canopy","pollinators"],"uses":["riparian","reforestation","windbreak","parks"],"cautions":["short_lived","pest_prone"],"image_url":"https://upload.wikimedia.org/wikipedia/commons/2/2c/20120904Alnus_glutinosa01.jpg","image_credit":"Wikimedia Commons, file 20120904Alnus_glutinosa01.jpg (see file page for author and licence)","sources":["https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/alder/","https://www.gbif.org/species/2876213","https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277813"],"data_note":null,"updated_at":"2026-11-08T01:00:46.205Z","page_url":"https://treerm.org/trees/alnus-glutinosa","markdown_url":"https://treerm.org/trees/alnus-glutinosa.md","regions":[{"country":"DE","region":null,"locality":null,"status":"native","note":null,"source_url":"https://www.gbif.org/species/2876213"},{"country":"FR","region":null,"locality":null,"status":"native","note":null,"source_url":"https://www.gbif.org/species/2876213"},{"country":"GB","region":null,"locality":null,"status":"native","note":null,"source_url":"https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/alder/"},{"country":"IE","region":null,"locality":null,"status":"native","note":null,"source_url":"https://www.gbif.org/species/2876213"},{"country":"SE","region":null,"locality":null,"status":"native","note":null,"source_url":"https://www.gbif.org/species/2876213"},{"country":"AU","region":"TAS","locality":null,"status":"adapted","note":"Introduced per WCVP","source_url":"https://www.gbif.org/species/2876213"},{"country":"NZ","region":null,"locality":null,"status":"adapted","note":"Introduced and naturalised; listed as a weed by Weedbusters NZ","source_url":"https://www.weedbusters.org.nz/what-are-weeds/weed-list/"}],"license":"CC-BY-4.0"}