Dwarf Mountain Ash – Sorbus reducta

By James Ellison

Originally published May 1994

The genus Sorbus is a larger group of trees and shrubs grown primarily for their showy fruit and Autumn foliage. Many of the species become sizeable shrubs or eventually attain tree size. However, there are a few species that rarely exceed one meter in height. The Dwarf Mountain Ash Sorbus reducta is one such species.

This charming dwarf species is native to Western China and Northern Burma. Dark, shiny green leaves are divided into serrated leaflets. These turn bronze-purple in the Autumn. Flat creamy flower clusters are produced in late Spring and are followed by beautiful rootsuckers and form small thickets, while other plants will remain as solitary specimens.

I was introduced to this species at The Memorial University Botanical Garden in St. John’s, Newfoundland. A small group of plants had formed a suckering thicket in a sheltered shady area in the woodland garden. I was told by the curator, Mr. Bernard Jackson, that a few had been put in the rockery but struggled to survive, possibly due to dryer conditions found in the rock garden media.

Dwarf Mountain Ash will do quite well in Nova Scotia and, although the hardiness of the species is not determined, it should grow well in Plant Zone 5. About 5 years ago I planted several seedlings at West Bay Road in Cape Breton. These plants are about 2′ in height and doing very well.

Sorbus reducta will usually come true from seed and is generally propagated in that manner. The seed should be stratified in moist peat or sand for at least a month, (actually they will sometimes start germinating during the stratification period), to break internal dormancy. One can usually expect a high percent of germination.

This unusual species of Sorbus can be found periodically at garden centers in NS. It combines very well with dwarf conifers, heathers and other dwarfs shrubs but seems to prefer semi-shade condition. In a rock garden situation it would probably be wise to add a bit of organic material and mulch to keep the root zone cool and moist. Sorbus reducta can also be utilized in foundation plantings. Its diminutive size insures that it will not outgrow its designated position quickly. Having both attractive berries and foliage will make it a desirable addition to any garden.