Fraxinus americana

RHS Plant Profile
American ash

Other common names

Canadian ash, white ash

Synonyms

Fraxinus biltmoreana
Fraxinus alba

Trees

Fast-growing, broadly-columnar, deciduous tree about 25m tall, with dark green leaves to 35cm long, composed of 3-5 tapered leaflets, turning yellow then purple in autumn. From spring to early summer small yellowish-purple flowers without petals are produced (male and female flowers are usually on separate plants, both are needed to produce the winged fruits). Winter buds are brown

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

Higher than 12 metres

Max Spread

wider than 8 metres

Size

Time to Maturity
20–50 years
Max Spread
wider than 8 metres
Max Height
Higher than 12 metres

Growing Conditions

Chalk Clay Loam Sand
Moisture
Moist but well–drained
pH
Alkaline or Neutral

Position

Full sun
Aspect
South–facing or West–facing or East–facing
Exposure
Exposed or Sheltered
Hardiness
H6

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Oleaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Spreading branched
Genus
Fraxinus are medium-sized to large, mostly deciduous trees with attractive pinnate leaves, sometimes conspicuous flowers and autumn colour, and distinctive winged fruits
Name Status
Correct
Plant Range
C & E North America

How to Grow

Cultivation

Excellent for woodland and coastal gardens where there is moist but well-drained alkaline or neutral soil and full sun. See tree cultivation

Propagation

Propagate by seed or grafting

Suggested planting locations and garden types

  • Coastal
  • Cottage and informal garden
  • Wildlife gardens

Pruning

Pruning group 1

Pests

Generally pest-free

Diseases

Ash dieback has recently been found in the UK. Restrictions have been put in place (from 29 October 2012) regarding both the importation of ash from abroad and the movement of ash within the UK. May also be susceptible to honey fungus