About
Alnus rubra is a medium-sized, fast-growing tree that can reach heights of approximately 19 meters. It features a narrow, pyramidal crown with branches that tend to droop. The leaves are large and lobed, displaying a dark green color on the upper side and a greyish hue underneath. Male catkins can grow up to 15 centimeters in length, while the tree's fruits are barrel-shaped and measure around 1.5 centimeters long.
About the genus
Alnus comprises robust deciduous trees and sizable shrubs characterized by their rounded foliage and, during winter, noticeable catkins.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Chalk, Clay, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- West-facing, South-facing, East-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H7
Plant details
- Plant type
- Trees
- Habit
- Columnar upright
- Foliage
- Deciduous
- Height
- Higher than 12 metres
- Spread
- 4-8 metres
- Time to full height
- 20-50 years
- Suggested uses
- Architectural, Wildlife gardens
- Native to
- Alaska to California
Care notes
- Cultivation
- This genus is noted for its ability to thrive in poor, wet conditions and is widely used in land reclamation
- Pruning
- Requires minimal pruning
- Propagation
- Propagate by seed in a seedbed as soon as ripe. Root hardwood cuttings in winter and softwood cuttings in summer. Bud grafting can be performed in late summer
- Pest resistance
- Generally pest-free
- Disease resistance
- May be susceptible to Phytophthora and honey fungus