Overview
Alnus hirsuta is a spreading branched, columnar upright trees in the genus Alnus, part of the Betulaceae family, with deciduous foliage. Alnus hirsuta grows best in full sun, and tolerates clay and loam soils and any pH. Its UK hardiness is rated H6. Suggested uses include architectural.
About
Alnus incana, the grey alder, tag alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners and is a common sight in swamps and wetlands. In the wild it grows across Amur, Buryatiya, Chita, Inner Mongolia, Japan and other regions. Grow it in full sun and clay and loam soil. In UK gardens it is very hardy across most of the UK (RHS H6). It works well for architectural. It tolerates soil of any pH, poorly-drained conditions and east-facing, north-facing, south-facing and west-facing aspects. Plant in well-drained soil in sun or partial shade.
Wikipedia contributors, CC BY-SA 4.0 — Alnus incana
About the genus
Alders are trees of the genus Alnus in the birch family Betulaceae. The genus includes about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes.
Wikipedia contributors, "Alder", CC BY-SA 4.0 — Alder
Growing conditions
Best soil and position for Alnus
- Sunlight
- Full sun
- Soil type
- Clay, Loam
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Poorly-drained
- Aspect
- East-facing, North-facing, South-facing, West-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H6
Plant details
Alnus hirsuta size, habit and characteristics
- Plant type
- Trees
- Habit
- Spreading branched, Columnar upright
- Foliage
- Deciduous
- Suggested uses
- Architectural
Care notes
Pruning and caring for Alnus hirsuta
- Propagation
- Propagate by hardwood cuttings or seed. For more advice see our information on how to propagate from seed (tree/shrub
- Pest resistance
- May be susceptible to alder leaf beetle, alder sucker and leaf-mining sawflies
- Disease resistance
- May be susceptible to phytophthora root rot and honey fungus
Frequently asked questions
Where is the best place to plant Alnus hirsuta?
Alnus hirsuta prefers full sun. It suits exposed and sheltered positions.
What soil does Alnus hirsuta need?
Alnus hirsuta grows best in clay and loam soil. It is happy in soil of any pH. Aim for soil that stays poorly-drained.
Is Alnus hirsuta hardy in the UK?
Alnus hirsuta has an RHS hardiness rating of H6, meaning it is very hardy, tolerating -20 to -15°C across most of the UK.
How do I propagate Alnus hirsuta?
Propagate by hardwood cuttings or seed. For more advice see our information on how to propagate from seed (tree/shrub.