tree

Grey alder

Alnus incana

Updated 4 Aug 2026 · AI-parsed entry

Grey alder (Alnus incana) — a tree, for Full sun, Medium water.

What it needs & gives back

↓ Needs

Lightfull sun to partial shade
Watermedium to high

↑ Gives back

Mulch_biomassmedium to high
Shademedium

Through the year

Through the year

JFMAMJJASOND
emergenceBud break and leaf emergence typically occur after the last spring frost and when air temperatures consistently rise above 5°C.
floweringFlowering occurs in early spring, usually in March, as days lengthen before leaf emergence.
fruitingFruits (small cones) develop over the summer, maturing approximately 4 months after flowering.
senescenceLeaves turn yellow and drop in autumn, triggered by the first frost and shortening day lengths.
dormancyThe tree enters dormancy after the first autumn frost, remaining dormant through winter.

Soil interactions

Drainagemoist to wet
Nitrogen fixingYes
MycorrhizalYes
Accumulatesnitrogen, calcium, magnesium
Soil textureloam, sand, clay
Organic matterHigh
Compaction toleranceMedium

Propagation

Methodsseed, cuttings, layering
Difficulty2 / 5
Establishes in~2 yr
Stratificationrequires cold stratification for 60-90 days
Self-seedingModerate
Divisionnot applicable

Wildlife & pests

Attractspollinators, birds
Can host diseasesalder canker