Tree · Betulaceae
Green alder
Alnus viridis · includes its varieties and subspecies
Green alder is recorded as native to 18 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 189 counties of those states by USDA PLANTS.
Key facts · USDA PLANTS
Green alder at a glance
- Native in
- 189 counties, across 18 states and territories
- Estimated cold hardiness
- Zone 1a PLANTS minimum temperature −62°F
- Mature height
- 10 ft PLANTS mature height
- Light and water
- Sun to part shade High water use
Estimated cold hardiness: zone 1a. PLANTS gives a minimum temperature of −62°F; zone 1a winters bottom out at −60°F, the coldest half-zone that stays within that limit.
Green alder is recorded as native to 18 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 189 counties of those states by USDA PLANTS.
Counties where it is native
The 15 counties with the most ZIP codes among the 189 where it is listed.
Native counties by state
- Alaska 21 counties
- California 5 counties
- Idaho 19 counties
- Maine 15 counties
- Massachusetts 3 counties
- Michigan 9 counties
- Minnesota 12 counties
- Montana 12 counties
- New Hampshire 8 counties
- New York 7 counties
- North Carolina 1 county
- Oregon 23 counties
- Pennsylvania 2 counties
- Tennessee 1 county
- Vermont 8 counties
- Washington 27 counties
- Wisconsin 13 counties
- Wyoming 3 counties
Growing traits
Values from the PLANTS characteristics record of a variety (ALVIC). “Not recorded” means PLANTS has no value; nothing here is estimated except the zone.
Growth
- Growth habit
- Shrub, Tree
- Duration
- Perennial
- Mature height
- 10 ft
- Growth rate
- Moderate
- Growth form
- Thicket Forming
- Shape
- Erect
- Lifespan
- Moderate
- Active growth period
- Spring and Summer
Light and water
- Shade tolerance
- Intermediate (sun to part shade)
- Moisture use
- High water use
- Drought tolerance
- None
- Tolerance of waterlogged soil
- High
- Precipitation range
- 12 to 60 in per year
Soil
- Soil textures
- Coarse and medium
- pH range
- 4.8 to 7
- Lime (CaCO₃) tolerance
- Low
- Salinity tolerance
- None
- Fertility requirement
- Medium
- Minimum root depth
- 20 in
Climate
- Minimum temperature
- −62°F
- Estimated cold hardiness
- Zone 1a and warmer
- Minimum frost-free days
- 80
- Fire tolerance
- Medium
Flowers, leaves and fruit
- Flower color
- Yellow
- Showy flowers
- No
- Bloom period
- Summer
- Foliage color
- Green
- Showy in fall
- No
- Keeps leaves
- No
- Fruit color
- Brown
Other
- Toxicity
- None
- Nitrogen fixation
- Low
- Nursery availability
- Routinely Available
- Family
- Betulaceae
- PLANTS symbol
- ALVI5
Source & data date
- Source
- USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).
- Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.
- USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
- Citation
- USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.
- Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
- Data date
- Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
- Scope
- Alnus viridis (PLANTS symbol ALVI5), including 2 varieties and subspecies folded into the species.
- Method
- A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources