A tree for all Seasons
Common Name: mountain ash, rowan tree
Botanical Name: Sorbus
Form: upright and narrow when young, then canopy broadens and rounds with age
Plant Type: deciduous tree
Mature Size: 20 to 40 feet x 10 to 20 feet
Growth: medium rate
Origin: Great Britain, Europe, Western Asia, Siberia, naturalized in northern USA & Canada
Hardiness Zone: 3 to 6
Foliage: alternate, compound matte green leaves are serrated, leaves comprised of 9-15 pinnate oblong leaflets, good fall colour from yellow, orange and, reddish-purple
Flowers: May, small white with 5 petals in flat clusters (corymbs)
Fruit: showy clusters of orangey-red berries (drupes) in late summer through winter
Exposure: sun to semi-shade
Soil: moist, acidic, well-drained
Uses: specimen, accent, wildlife gardens, shade tree
Attracts: birds, wildlife, pollinating insects
Propagation: seed, softwood cuttings
Pruning: winter, when dormant
Problems: bacterial fire blight, scab, crown gall, aphids, drought stressed trees vulnerable to borers and cankers
This delightful small tree has many attributes with its flowers, berries, fall foliage and small stature. It’s just the right size to provide shade in small urban gardens, clusters of little white flowers in May are profuse and relished by pollinators, large clusters of hanging colourful berries follow and are very ornamental. Last but not least, their foliage colours up nicely in autumn.
Birds flock to devour the orange berries, however cultivars with pink and white fruit are not so popular, therefore they may stay on the tree into spring. The berries carry viable seeds, which means they tend to self-propagate.
Although mountain ash are pretty tough, they don’t tolerate drought. Their distress is noted by foliage that turns inwards so only the back of the leaves are visible. This gives the tree a greyish cast. Trees eventually decline if they are suffer from drought year after year.
Fire blight is a serious issue with mountain ash. Look for stems and leaves that appear burnt and scorched as though they had been in a fire. Fire blight’s tell-tale symptom blackened stems that become hooked like a shepherd’s hook.
Warm, wet and humid conditions favor this disease. There’s no simple and easy cure for fire blight so it’s commonly recommended to not to even try, however you can try the following – no guarantees though. Cut off infected portions, well beyond the infected stems, and disinfect pruners after each cut. Spray the entire tree thoroughly with a Bordeaux Mix in early spring according to the instructions. Clean up all foliage before winter, and remove infected parts asap.
The Wizard’s Tree
Folklore revolves around mountain ash as it was considered a mystical plant of the wizards. Part of its attraction and magical powers was the ability of the bright fruit remaining on the tree once the leaves had fallen. Its wood was used as dowsing rods for numerous substances especially water hidden underground. The berries were also collected and used as medicine. No wonder it was named The Wizard’s Tree.