Showy Mountain Ash
Sorbus decora
Family: Rosaceae
What it is like
Sorbus decora is a deciduous Tree growing to 10 m (32ft) by 8 m (26ft). See above for USDA hardiness. It is hardy to UK zone 2. It is in flower from May to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. The plant can tolerates strong winds but not maritime exposure.
Height (m): 10
Where it is found
Woods, rocky slopes and shores. Found in various soils and conditions.
North-eastern N. America - Labrador and Newfoundland to Quebec, south to Iowa and Maine.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Fruit - raw or cooked in preserves etc. The taste is best after a frost. The fruits are about 7 - 10mm across and are borne in dense clusters.
Medicine
Rating: 1
A decoction of the inner bark, taken from the stem base, has been used as a wash and poultice in the treatment of rheumatism. The decoction can also be taken internally in the treatment of a backache. A decoction of the peeled stems has been drunk in the treatment of backaches.
Analgesic: Relieves pain.
Antirheumatic: Treats rheumatism.
Other
Rating: 2
This species is capable of growing in exposed conditions in poor soils, and so could be used in re-afforestation as a pioneer plant to provide suitable conditions for other woodland trees to be established. Wood - close-grained, soft, moderately light with little strength, it is of no commercial value.
Pioneer: Plants, usually trees and shrubs, that can be used to reforest land.
Wood: A list of the trees and shrubs that are noted for having useful wood.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
Succeeds in most reasonably good soils in an open sunny position. Dislikes dry soils. Tolerates light shade, though it fruits better in a sunny position. This species is able to grow in poor soils and to become established on exposed broken ground. Plants are susceptible to fireblight. Closely related to S. americana. The plant is heat tolerant in zones 8 through 1. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a standard with a non-suckering single trunk. The root pattern is flat with shallow roots forming a plate near the soil surface.
Propagating it: Seed - best sown as soon as it is ripe in a cold frame. If you have sufficient seed it can be sown in an outdoor seedbed. Stored seed germinates better if given 2 weeks warm then 14 - 16 weeks cold stratification, so sow it as early in the year as possible. Prick out the seedlings into individual pots when they are large enough to handle. Seedlings are very slow to put on top-growth for their first year or two, but they are busy building up a good root system. It is best to keep them in pots in a cold frame for their first winter and then plant them out into their permanent positions in late spring.
Best place to grow: Woodland Garden Canopy; Secondary; Sunny Edge;
Habit: Tree
Hardiness: 0-0
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
The seeds probably contain hydrogen cyanide. This is the ingredient that gives almonds their characteristic flavour. Unless the seed is very bitter it should be perfectly safe in reasonable quantities. In small quantities, hydrogen cyanide has been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death.