trefle.io · Taken Oct 11, 2016 by Tela Botanica − Barbara MAI (cc-by-sa)
Betulaceae
Grey alder
Alnus incana
Also known as Speckled alder, Gray alder, Betula incana, Alnus incana var. lobata
Native Plants · Trees & Shrubs · Tree · Deciduous · Nitrogen-Fixing · Streambank · Fast Growing · Alder · Betulaceae · Wildlife · Riparian · Soil Improvement
Grey alder is a fast-growing deciduous tree well suited to moist or wet soils, streambanks, and challenging sites where most trees fail to thrive. It is nitrogen-fixing, improving soil fertility for surrounding plants, and requires very little maintenance once established. Plant in full sun to partial shade with reliable moisture, especially during the first two growing seasons.
Growing conditions
The details behind the basics
- Daily light
- 6 hours
- Watering
- Water deeply to encourage deep rooting; allow soil surface to dry slightly between waterings · Every 7-14 days when young; established trees are largely self-sufficient
- Maintenance
- Low
- Soil
- loam
- Soil pH
- 5–7
- Temperature
- -20°F to 85°F
- Cycle
- Perennial
- Propagation
- Seed
Hardiness
USDA 5a-9b
Form & growth
Mature size and habit
- Mature height
- 12 in – 3 ft
- Spread
- 2 ft
- Spacing
- 240 in apart
- Growth rate
- Fast
- Root depth
- Medium
- Flowers
- No
- Foliage
- Green · Coarse
Ecology & origin
Where it belongs and what it brings
- Native to
- Alaska, Albania, Alberta, Argentina South, Arizona, Austria, Azores, Baltic States, Belarus, Belgium, British Columbia, Bulgaria, California, Central European Rus, Colorado, Connecticut, Czechoslovakia, Denmark, East European Russia, Finland
- Attracts
- Bees, Birds, Butterflies
Sources: trefle, usda
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