Not the plant you're looking for? Search over 300,000 plants

Alnus rubra

red alder

A medium-sized tree, to around 19m, fast-growing with a graceful habit, producing a narrow pyramidal head with rather pendulous branches. Leaves large, lobed, dark green above, greyish beneath. Long male catkins to 15cm. Fruits barrel-shaped, to 1.5cm long

Other common names
Californian red alder
Oregon alder
see moretag alder
Synonyms
Alnus oregana
Buy this plant
Size
Ultimate height
Higher than 12 metres
Time to ultimate height
20–50 years
Ultimate spread
4–8 metres
Growing conditions
Chalk
Clay
Loam
Sand
Moisture
Moist but well–drained
pH
Acid, Alkaline, Neutral
Colour & scent
StemFlowerFoliageFruit
Spring Yellow Green
Summer Green Brown
Autumn Green Brown
Winter
Position
  • Full sun
Aspect

West–facing or South–facing or East–facing

Exposure
Exposed or Sheltered
Hardiness
H6
Botanical details
Family
Betulaceae
Native to the UK
No
Foliage
Deciduous
Habit
Columnar upright
Genus

Alnus are vigorous deciduous trees and large shrubs with rounded leaves and often conspicuous catkins in winter

Name status

Correct

Plant range
Alaska to California

Advertise here

How to grow

Cultivation

Thrives in moderately fertile, moist but well drained soil in full sun

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

Suggested planting locations and garden types
  • Architectural
  • Wildlife gardens
  • Low Maintenance
  • Hedging and screens
Pruning

Requires minimal pruning

Pests

Generally trouble free

Diseases

Prone to Phytophthora root rot

My Garden

Your free RHS gardening coach

Keep track of your plants with reminders & care tips – all to help you grow successfully

My plants
My calendar

My plants

My calendar

My ideas
Manage membership

My ideas

My advice

Get involved

The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.