Black alder
Black alder
Alnus glutinosa
tree☀️ full-sun🪴 moist-loam📏 tall🌡️ RHS H7
📋Quick Facts
Height
15.0-25.0m
Spread
8.0-12.0m
About
Large alder for riverbanks and wet ground; fixes nitrogen.
Top tip
Black alder loves river edges and wet soils; coppice or pollard if you want to keep it smaller.
Also known as: Amieiro-negro, Ontano nero, Aliso negro, Zwarte els, Olsza czarna, Schwarzerle, Aulne glutineux, Black alder
Pest Resilience
4/5 — Good resilience
Alder leaf beetle and phytophthora can be issues; generally a tough pioneer species.
The black alder year in your garden
Dispatching imaginary bots to check your garden out...
What to do now
How to Propagate
🌰Seed
Easy✂️Cutting
ModerateHardiness Zones
H1a (tender)H7 (very hardy)
RHS H7
USDA 4–5 equivalent