Mountain Ash, Rowan (Sorbus)

Mountain ash, rowan (Sorbus)

Mountain ash, or rowans, are attractive, deciduous, ornamental trees, many of which are suitable for even small to average-sized gardens. They look fabulous in spring, covered in their flowers, and again in autumn when their fruit and autumn foliage provide more interest and colour.


How to grow mountain ash

Cultivation

The majority of mountain ash species and varieties aren’t too fussy about their position – they will grow in open, sunny sites or partial shade. They prefer a fertile, well-drained soil enriched with lots of organic matter, which holds plenty of moisture in spring and summer, doesn’t dry out or become waterlogged. Mountain ash trees will grow in just about all soils types.

Mountain ash varieties

  • Sorbus aucuparia, the common mountain ash, is an upright tree with clusters of white flowers in late spring, followed by orange-red berries in autumn and yellow autumn leaf colours.
  • Sorbus cashmiriana can be grown as a large, spreading shrub or small tree. The pink flowers are followed by white fruit in autumn.
  • Sorbus commixta ‘Embley’ is an upright, medium-sized tree with creamy-white flowers, deep red fruit and bright red and orange autumn leaf colours.
  • Sorbus ‘Eastern Promise’ is a small, rounded tree with clusters of small white flowers, rose-pink berries in autumn and purple and orange-red autumn leaf colours.
  • Sorbus ‘Joseph Rock’ is an upright tree with white flowers, yellow berries and orange, purple and red autumn leaf colours.
  • Sorbus reducta is a suckering shrub with small clusters of white flowers followed by pale pink to white fruit and purple autumn leaf colours.
  • Sorbus sargentiana is a spreading medium-sized tree with white flowers, large clusters of red berries and orange-red autumn leaf colours.

Mountain ash/rowan tree branch closeup

Planting mountain ash

Plant bare-root trees between November and March, and container-grown ones any time of year, but preferably in autumn, winter or spring. Dig a hole 60x60cm (2x2ft) and 30cm (12in) deep. Add a layer of organic matter – such as compost or well-rotted manure – to the base of the hole and dig in. Place the roots in the planting hole and adjust the planting depth so that the tree is planted at the same depth as it was originally growing and the top of the roots are level with the soil surface.

Mix in more organic matter with the excavated soil and fill in the planting hole. Stake the tree with a rigid tree stake and two tree ties so that it is fully supported against the prevailing winds. Water in well, apply a granular general feed over the soil around the tree and add a 5-7.5cm (2-3in) deep mulch of well-rotted garden compost or bark chippings around the root area.

If planting in the lawn, create a turf-free circular bed around the tree with a minimum diameter of 60cm (2ft).

Suggested planting locations and garden types

Flower borders and beds, focal point, city and courtyard gardens, natural and wildlife gardens, cottage and informal gardens.


How to care for mountain ash

Mountain ash/rowans are low-maintenance trees, needing little care and attention once established.

They may need watering during prolonged dry periods in summer – particularly in the first few years to ensure they establish well. Feed with a general granular plant food in spring.

Mountain ash/rowans need little or no maintenance pruning, except to remove dead, diseased or dying growth and to thin out overcrowded and rubbing branches. If pruning is needed, it is best carried out any time from late autumn to early spring.

Flowering season(s) Spring
Foliage season(s) Spring, Summer, Autumn
Sunlight Partial shade, Full sun
Soil type Chalky, Clay, Loamy, Sandy
Soil pH Neutral
Soil moisture Moist but well-drained
Ultimate height Up to 10m (33ft), depending on species and variety
Ultimate spread Up to 8m (26ft) depending on variety
Time to ultimate height 20-30 years