This species is not a true ash tree like the European Ash. European Mountain Ash trees have ash-like leaves, but they are members of the rose family; true ash trees (Fraxinus spp.), are members of the olive family. The European Mountain Ash is native to Western Asia and Europe.
Botanical Name
The botanical name for this member of the Rosaceae family is Sorbus aucuparia. Other well-known members of this family include roses, strawberries, the Prunus genus (which contains apricots, almonds, cherries, nectarines, peaches, and plums, among others), Cotoneaster spp., raspberries, and blackberries.
Common Names
Common names that might be applied to this tree include European rowan, mountain ash, rowan, and European mountain ash.
Preferred USDA Cold Hardiness Zones
USDA Cold Hardiness Zones 3 through 6 are the recommended zones for this tree. It will not grow well south of USDA Zone 6.
Size and Shape
This tree reaches a height of 20 to 40 feet with an 8 to 20 foot spread as it forms into an narrow, upright specimen with an oval or round crown.
Light
This tree requires full sun at least six to eight hours per day.
Foliage, Flowers, and Fruit
The pinnately compound leaves are arranged alternately on the stem, each one featuring 9 to 15 leaflets. White flowers are produced in May and are borne in cymes (clusters). After the flower show, the tree is covered with clusters of red-orange pome fruits.
Design Tips
Invite birds into your landscape by planting one of these trees; their fruit is a favorite treat and the red berries add much-needed color to a winter garden.
Growing Tips
Perform a soil test to ensure the soil is acidic, in the range of 4.5 to 6.0, which this tree prefers. You can add amendments to acidify the soil if the soil pH is too high. This tree does best in moist, well-drained soils. As the common name suggests, this tree prefers cool mountain climates and dislikes hot and humid summers,
Maintenance and Pruning
Fire blight can be spread by pruning if the conditions are right (very warm). Prune this tree at winter’s end during the tree’s dormant period.
Pests and Diseases
Pests
Aphids Apple fruit moth (Argyresthia conjugella) Blister mites Borers Deer Mountain-ash sawfly larvae (Pristiphora geniculata) Scales such as the oystershell scale (Lepidosaphes ulmi)
Diseases
Apple scab (Venturia inaequalis) Botryosphaeria dieback and canker (Botryosphaeria dothidea) Cedar-quince rust (Gymnosporangium clavipes) Cytospora canker (Cytospora spp.) Bacterial fire blight (caused by Erwinia amylovora) Powdery mildew
