Wednesday, April 14, 2010

Sorbus - Mountain Ash

A genus of close to 100 species of trees and shrubs that are distant relatives of the Rose. The 5 petalled flowers are borne in clusters in late spring and are followed by very attractive bunches of fruit that ripen in autumn and attract songbirds.
The fruits of many species are valuable for use in the making of pies, jellies and sauces. The fruits are rich in pectin.
They prefer full sun to partial shade on deep, cool ( mulched ), light, fertile, well drained soil but are soil tolerant. They do however mostly prefer cool climates and the pinnate leaves species do not enjoy drought. The majority of Sorbus actually require cold winters to thrive.
Pruning if needed is done in autumn and winter. On the more arboreal types; young trees should be pruned to a single leader, feathered and thinned.
Fireblight can cause severe damage in some areas. Pear slug can also deskeletonize the foliage. Borers can be a problem in the eastern U.S. and southern Ontario, Canada however do not appear to be a problem in the Pacific Northwest.
Propagation can be from stratified seeds or grafting. Semi-mature cuttings or softwood cuttings taken in summer and inserted under mist have been used for S. alnifolia with a success rate of almost 50%. Likely many species of Sorbus will root from semi-mature cuttings taken from June – August and inserted under mist.
The use of growth hormones will almost
certainly enhance results. Trees should be planted while dormant, either late autumn or early spring.

Sorbus alnifolia ( Korean Mountain Ash )
A fast growing, dense, long-lived, medium-size tree, reaching up to 50 + feet, that is native to the Ussuri region of Russia, China ( esp. Manchuria ), Korea and much of Japan. Some records include: fastest recorded growth rate - 4 feet; 10 years - 20 x 20 feet; 18 years - 53 x 20 feet; ; 22 years - trunk diameter of 22 inches; 50 years - trunk diameter of 2.5 feet; largest on record - 80 x 60 feet; largest in Massachussets - 70 x 60 feet in Boston.
The simple, deeply double toothed, pointed, ovate leaves are up to 6 x 3 inches in size. The foliage appearing very early in spring is downy bright green turning to glossy deep green above, light green beneath. The leaves turns from intense golden-yellow to scarlet-red during autumn.
The 0.5 inch white flowers are borne in clusters up to 3 inches across during mid-spring.
They are followed by rounded fruits that are yellow turning to bright red, up to 0.5 inches across, persisting long after the leaves fall.
The stems are red-brown when young.
The smooth bark is silvery and beech-like.
Hardy zone 3 to 8. Heat and clay tolerant. Borer and disease resistant.

* photo taken on March 28 2010 @ U.S. National Arboretum, D.C.

* photo taken on April 11 2010 @ U.S. National Arboretum

* photo taken on August 3 2010 @ University of Guelph Arboretum, Ontario

* photos taken on October 17 2010 @ U.S. National Arboretum, D.C.



'Redbird'
Extremely persistant rosy-red berries.

'Skyline'
Reaches up to 40+ x 15 feet, with an upright columnar habit. The foliage turns to yellow during autumn.

Sorbus americana ( American Mountain Ash )
A small tree native to central and eastern North America ( from southeast Manitoba to Lansdowne House, Ontario to Armstrong, Ontario to Moosonee, Ontario to Labrador and Newfoundland; south to Minnesota to Pennsylvania ). Some records include: fastest recorded growth rate - 3 feet ( 6 feet on stump sprouts ); largest on record - 90 x 45 feet with a trunk diameter of 3 feet.
The pinnate leaves, up to 12 inches in length are composed of 11 to 19 toothed, pointed oblong leaflets up to 4 x 1 inches in size. The foliage appears early in spring and is blue-green above and gray-green beneath, turning to red late in autumn.
The 0.25 inch white flowers are borne in dense clusters, up to 8 inches across, duriung late spring.
They are followed by bright red berries up to 0.25 inches wide in hanging clusters.
The fruits often persist into January.
The stout twigs are red brown.
The bark is gray and smooth with horizontal lenticels. On very old trees that bark breaks into scaly ridges.
Hardy zone 1 to 5 ( 6 ). The American Mountain Ash does not enjoy hot summers and late summer leaf drop is common in zone 6 in the eastern U.S. It is also prone to fireblight.


* photos taken on Aug 4 2013 in Bayfield, Ontario

* photo taken by USDA-NRCS PLANTS Database

* historic archive photos


Sorbus amurensis ( Amur Mountain Ash )
An extremely cold hardy tree very similar to Sorbus aucuparia, that is native to the cold mountainous interior of South Korea. Some records include: 20 years - 17 feet; largest on record - 27 feet. It may be nothing more than a subspecies of Sorbus pohuashanensis.
The pinnate leaves, up to 8 inches in length are composed of up to 15 ovate leaflets up to 2 x 0.6 inches. The foliage is deep green above, whitish beneath. The leaves turn to intense orange-red during autumn.
The creamy-white flowers are borne in clusters up to inches across.
They are followed by orange berries that persist through winter.
Hardy zones 3 to 6.

Sorbus anglica ( Anglican Whitebeam )
A slow growing, strong branched, small tree native to Britain and Ireland. It is rare in Ireland and endangered in England with only 600 trees remaining.
Some records include: 38 years - 27 x 20 feet with a trunk diameter of 1 foot; largest on record - 35 feet with a trunk diameter of 1 foot.
The deeply double-toothed, broad-oval leaves are up to 4.5 x 3 inches in size.
The foliage is deep green above and white felted beneath, turning to russet in autumn.
The white flowers are borne in clusters.
They are followed by deep pink-red fruits.
Hardy zone 7 to 9

* excellent photo link found on internet
http://www.arkive.org/whitebeam/sorbus-anglica/

Sorbus aria ( Whitebeam )
A dense, attractive, broad-crowned, medium-sized tree native to the mountains of central and northern Europe. Some records include: fastest recorded growth rate - 3 feet; 20 years - 60 x 40 feet; largest on record - 105 x 30 feet with a trunk diameter of 6 feet.
The sharply double-toothed, broad-elliptical leaves are up to 6 x 2.5 inches in size. The foliage is white felt covered when young turning to glossy deep-green above and densely white-felted beneath. The foliage persists late during autumn often turning orange and golden-yellow before falling.
The 0.6 inch white flowers are borne in flattened clusters, up to 4 inches across, during late spring.
They are followed by glossy scarlet-red berries up to 0.65 inches wide that are speckled with pale lenticels. The berries are borne on showy clusters and the yield is up to 30 pounds per tree
The smooth gray bark develops rugged cracks on older trees. The heavy wood is valuable for making of chairs.
Hardy zone 2 to 8 and tolerant of heavy clay, urban conditions, shallow chalk soils, pollution and salty sea breezes. Prone to fireblight.
Propagation of cultivars is from softwood cuttings taken in summer.

* historic archive photos

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id39559/

'Aurea'
Foliage is golden-yellow.

'Gigantea'
Very vigorous with large foliage, up to 9.7 x 6 inches.

'Lutescens'
Conical in habit with foliage that is silver hairy at first turning to bright green.

'Majestica'
Large leaves, up to 7 inches on a vigorous, very broad crowned tree.

'Quercoides'
Compact growing with lobed, Oak-like leaves.

Sorbus aronioides
A very beautiful, slow growing, flat topped shrub to small tree ( if trained as such and with age ), that is native to southern China and northern Burma where it is very rare. It may reach up to 12 x 13 feet in 15 years, estimated mature size may be around 30 feet with some reaching 50 feet.
The handsome, simple, toothed, obovate or elliptic leaves are up to 6 x 2.4 inches.
The leaves have 7 or 8 prominent pairs of alternately arranged veins.
The foliage is deep green above; light gray-green beneath; turning yellow-orange in autumn.
The white flowers are borne in dense terminal clusters, up to 3 inches across during late spring.
They are followed by large terminal clusters of fruit ( each up to 0.4 inches ) that are yellow-green with purplish-bloom on the sunny side.
The twigs are purplish-brown with white lenticels.
Hardy zones 6 to 8 thriving in much of the Pacific Northwest as long as soil is kept consistantly moist and cool ( mulching helps ) during summer. This species is unlikely to grow well in the hot humid east. This exceptionally beautiful Sorbus is not bothered by disease. Wrap trunks of young trees during winter to protect from chewing rabbits and sunscald. Also mulch around trees since lawn mower damage can easily kill these trees.

Sorbus arranensis ( Scotish Whitebeam )
Among the worlds most endangered plants, in 1980 there were only 283 mature trees of this species remaining worldwide. A rather erect, oval to rounded tree, the largest on record - 40 feet with a trunk diameter of 13 inches.
The attractive, toothed and lobed, ovate leaves are glossy mid-green above. The foliage turns to golden-yellow during autumn.

* photo of unknown internet source



* excellent photo link found on internet
http://www.arkive.org/whitebeam/sorbus-arranensis/

Sorbus aucuparia ( European Mountain-Ash )
Also called Rowan, it a very vigorous, medium-size tree native to much of northern Eurasia. Some records include: fastest recorded growth rate - 7 feet; 20 years - 50 x 33 feet; largest on record - 95 x 60 feet with a trunk diameter of 4.6 feet; largest in Canada - 60 feet with a trunk diameter of 32 inches @ Strasburg ( near Kitchener ), Ontario; longest lived - 100 + years.
The pinnate leaves, up to 16 inches in length are composed of 11 to 19 sharply-toothed, taper-pointed, oblong leaflets up to 3 x 1 inches in size. The foliage is deep green above, lightly hairy blue-green beneath turning to orange and red late in autumn.
The creamy-white flowers are borne in clusters, up to 6 inches across, during late spring.
They are followed by brilliant orange-red rounded fruits up to 0.5 inches wide that are borne in heavy clusters. A single tree may produce up to 50 pounds or more of fruit per year. The berries are used to produce jellies and preserves however can be poisonous if eaten raw.
The bark is gray and smooth. The twigs are glaucous purple with hairy whitish buds.
Hardy zones 1 to 6, it thrives even in Alberta's harsh climate including as far north as Fort McMurray. It requires acidic soil and is short lived on shallow limestone soils.

* photos taken on August 2 2010 in Bayfield, Ontario




* photo of unknown internet source


* photo taken on Aug 1 2013 in Goderich, Ontario

* photo taken on Aug 2 2013 in Stratford, Ontario

* historic archive photos


'Aspleniifolia'
Deeply cut ferny leaflets are hairy beneath.

'Beissneri'
Erect and compact in habit, reaching a maximum size of 50 feet with a trunk diameter of 15 inches. The foliage is yellow at first turning to medium green.
The young stems are red and the bark on older stems is bright orange.

'Black Hawk'
Similar to species but may be more tolerant of climate extremes in midwestern North America.

'Burka'
From Russia with abundant, very large ( much larger than specie ) red-orange sweet tart fruit.

'Cardinal Royal'
Vigorous and upright-oval; reaching around 50 x 40 feet or sometimes more.
Has very deep green foliage that contrasts well with the dark red fruits.

'Edulis'
Larger leaflets up to 4 x 1 inches. It is very heavy fruiting and the fruit is sweet. 450 pounds of fruit are reported to have been yielded in a single year from 14 trees of 30 years of age in Germany and were turned into 230 pounds of jelly.
This is the best variety for use in preserves.

* photos taken on Aug 4 2013 in Bayfield, Ontario

* photo taken by Milan Havlis, owner of central Europe's premier plant nursery


'Fastigiata'
Stiff upright shoots form a narrow crown. Some records include: 20 years - 20 x 6.5 feet; largest on record - 57 x 17 feet with a trunk diameter of 1.5 feet.
The fruits are large.

'Pendula'
Broad crowned and weeping. Some records include: 20 years - 20 x 33 feet; largest on record - 50 x 66 feet.

subsp rufoferruginia 'Longwood Sunset'
Very fast growing, up to 6 feet per year; is similar to Sorbus aucuparia but is highly disease, heat and drought resistant.
Foliage turns stunning red in autumn and the berries are intense brilliant orange.

'Russica'
Leaflets are larger, up to 3.5 x 1.3 inches

'Sheerwater Seedling'
Upright and conical, very vigorous. The berries are orangish-red.

var Sibirica ( Siberian Mountain Ash )
A subspecies or considered a separate species by some, that is native to Siberia and northern Mongolia. It forms a small tree, reaching a maximum height of 60 feet but rarely exceeding 30 feet.
The leaves, up to 8 inches in length, are composed of oblanceolate leaflets, up to 2 x 0.8 inches in size. The very attractive foliage is bright green above, gray-green beneath. The foliage turns to golden-yellow during autumn.
The white flowers are borne on dense clusters up to 5 inches across.
They are followed by juicy, rounded, large, orange-red berries up to 0.4 inches wide.
Hardy zones 1 to 5 ( tolerating as low as -58 F ) in full sun. It is propagated by seed.

'Xanthocarpa'
Golden-yellow fruits.

Sorbus austriaca
A deciduous, small tree, reaching up to 33 ( rarely over 20 ) feet, that is native to mountain of central Europe ( from Switzerland to Austria Hungary to Romania; south to Bulgaria ). The subspecies sp. croatica is found exclusively within Velebit Mountain within Croatia. It is closely related to Sorbus intermedia.
The shallowly-lobed, broadly-elliptical leaves are up to 8 ( rarely over 5 ) inches in length. The foliage is mid-green above; downy grayish-white beneath; turning to golden-yellow during autumn.
The white flowers are borne in clusters during late spring.
They are followed by rounded, red berries, up to 0.5 inches wide, during early to mid autumn.
Hardy zones 4 to 8 in full sun on just about any moist, fertile, well drained soil. It thrives in the Ottawa Valley of Canada but is virtually unknown elsewhere in North America.

Sorbus bristoliensis ( Bristol Whitebeam )
A small tree, reaching a maximum height of 60 ( rarely over 33 ) feet with a trunk diameter of 1 foot, that is only found in the wild in Avon Gorge in England where less than 300 plants remain. It is endangered with extinction in the wild. It is related to Sorbus latifolia. In the U.S., it can be found in cultivation at Dawes Arboretum in Ohio. It is long-lived with trees known to survive as long as 217 years, and even longer is certainly possible.
The toothed, elliptical leaves are glossy deep green above, gray downy beneath. The foliage turns to orange-red during autumn.
It bears orangish-red fruits, each up to 0.4 inches wide, during autumn.
Hardy zones 5 to 7 ( also 8 in maritime climates ).

Sorbus caloneura ( Small-leaved Whitebeam )
A small bushy tree that is native to China where it is rare. Some records include: fastest recorded growth rate - 2.5 feet; 20 years - 17 feet; largest on record - 40 x 30 feet with a trunk diameter of 15 inches.
The deeply-veined leaves appear very early in spring and are simple, double-toothed and oval, up to 5 x 3 inches. The foliage is often bronze or orange-red at first before turning to bright green then later to mid-green above, gray-green below. The foliage often turns to intense red during autumn.
The creamy-white flowers up to 0.4 inches wide with purple anthers are borne on clusters, up to 3 inches wide, during mid spring. They are followed by golden-brown pear-shaped fruits, up to 0.5 inches in autumn.
The branches are dark red-brown.
Hardy zones 5 to 8 ( possibly 4b as it has thrived at Dominion Arboretum in Ottawa, Canada ). Heat tolerant, it thrives in the Mid Atlantic. Not prone to disease.

* photo taken on March 28 2010 @ U.S. National Arboretum, D.C.



Sorbus cashmiriana ( Kashmir Sorbus )
A very rare vigorous, open, graceful, rounded small tree native to forests in the Kashmir region of the Himalayas.
Some records include: fastest recorded growth rate - 2 feet; 20 years - 40 x 40 feet; largest on record - 50 x 40 feet with a trunk diameter of 11 inches.
The pinnate leaves, up to 8 inches in length are composed of up to 19 sharply toothed, smooth leaflets up to 2 x 0.7 inches. The foliage is rich deep green above and gray-green beneath; turning to red during autumn.
The pinkish-white flowers up to an inch across are borne in large open clusters up to 7 inches across in late spring.
They are followed by striking white berries that give excellent contrast to the foliage. The berries, up to 0.65 inches wide, carried on red stalks, are very persistent.
The bark is smooth and reddish-gray.
Hardy zone 4 to 7 ( possible zone 3 if sheltered ). Thrives in northern Europe and even parts of coastal Alaska.
Propagation is from seed in autumn or softwood cuttings taken during the summer.

* photo taken on August 3 2010 @ University of Guelph Arboretum, Ontario

* photo taken by Milan Havlis, owner of central Europe's premier plant nursery


'Chinese Lace'

* photo taken by Milan Havlis, owner of central Europe's premier plant nursery


'Kirsten Pink'
Pink berries

Sorbus chamaemespilus ( Dwarf Whitebeam )
A shrub native to mountains of central and southern Europe.
Some records include: fastest recorded growth rate - feet; 20 years - ; largest on record - 12 x 6 feet.
The simple finely serrate, oval leaves are up to 4 x 1.5 inches. The foliage is deep green above, yellowish-green felted beneath; turning excellent fall color.
The deep pink flowers are borne in clusters.
They are followed by oval red fruit up to 0.5 inches.
Hardy zones 5 to 9

* excellent photo link found on internet<br /> http://www.biolib.cz/en/taxon/id297895/

Sorbus commixta ( Japanese Rowan )
A handsome, moderate growing, broadly-conical, medium-sized tree native to mountain forests of Sakhalin, the southern Kuriles, Korea and much of Japan. Some records include: fastest recorded growth rate - 5 feet; 5 years - 13 x 7 feet; 15 years - 25 feet ( Ottawa, Ontario ), 20 years - 30 feet; largest on record - 60 x 30 feet with a trunk diameter of 2 feet.
The pinnate leaves, up to 12 inches in length are composed of 13 to 17 fine, sharply-toothed, taper-pointed leaflets up to 4 x 1 inches in size. The foliage is bronze-red at first, turning to glossy light green above, blue-green beneath. The foliage turns to intense orange and red during autumn. Trees originating from Sakhalin seed source typically has longer leaflets where others tend to be 3 inches or under.
The white flowers, up to 0.35 inches wide are borne in clusters, up to 6 inches across, during late spring.
They are followed by very persistent, glossy scarlet-red berries, up to 0.5 inches across, borne on large clusters.
The conical buds are up to an inch in length.
The silvery-gray bark is smooth; becoming fissured on very old trees.
Hardy zone 4 to 8 ( possibly 3b for Sakhalin seed source ). Resistant to fireblight and also heat tolerant making this one of the best Sorbus for the Mid Atlantic and other parts of the eastern U.S. and Ontario, Canada. It also thrives in the Pacific Northwest.

* photos taken on May 8 2010 @ U.S. National Arboretum, D.C.




'Embley'
Foliage turns scarlet-red in autumn and persists into winter.
Hardy north to zone 3

'Ethel's Gold'
Bright green foliage constrasts with golden-yellow fruits.

'Jermyns
Very intense fall color. Orange-red fruits in large clusters.

Sorbus decora ( Showy Mountain Ash )
A small tree native to northeastern North America ( from central Manitoba to far northern Ontario to northern Quebec to all of Labrador & Newfoundland; south to northern Minnesota to northern Indiana to Kincardine, Ontario to Trenton, Ontario to northeast Pennsylvania to Massachusetts ). Some records include: fastest recorded growth rate - 3 feet; largest on record - 70 x 32 feet with a trunk diameter of 2 feet; largest in Michigan - 60 feet @ Gould City. It has darker green foliage and is even more ornamental than Sorbus americana.
The pinnate leaves are composed of 13 to 17 tooth-edged, narrowly-elliptical leaflets up to 3 x 2 inches ( the terminal leaflet which is the largest ) in size. The blue-green foliage turns very attractive orange and scarlet-red in autumn.
The white flowers are borne in rather loose clusters up to 4 inches across borne in spring.
They are followed by dense clusters of bright scarlet-red berries that often persist until mid-winter.
Hardy zone 1 to 5 requiring cool to cold climates. It thrives even in central Alaska. Fireblight resistant and also pollution tolerant.

* photo taken on August 3 2010 @ University of Guelph Arboretum, Ontario


* photos taken on July 14 2016 in Tobermory, ON


Sorbus discolor ( Snowberry Sorbus )
A small tree native to northern China. Some records include: largest on record - 50 x 32 feet with a trunk diameter of 2 feet.
The pinnate leaves, up to 10 inches in length are composed of up to 15 leaflets up to 3 inches in length. The foliage turns brilliant red in autumn.
The creamy-white flowers are borne in clusters up to inches across.
Hardy zone 2 to 7

Sorbus domestica ( Service Tree )
A long-lived, massive, oval to spreading, large tree native from south and eastern Europe to western Asia; south into northern Africa. It is endangered in Switzerland, Austria and the British Isles, rare in Spain. Some records include: fastest recorded growth rate - 2 feet; 20 years - 40 x 20 feet; largest on record - 105 x 60 feet with a trunk diameter of 5.2 feet; largest in Maryland - 74 x 40 x 5 feet in Baltimore City; longest lived - 600 years.
The pinnate leaves, up to 10 inches in length are composed of 13 to 21 sharply-toothed, forward pointing, oblong leaflets up to 3.5 x 0.5 inches in size. The foliage is smooth glossy deep green above and downy beneath; turning to yellow or red during autumn.
The white flowers, up to 0.65 inches wide are borne on very showy, large, domed clusters up to 6 inches across in late spring.
They are followed by relatively large, pear-shaped berries, up to 1.3 inches wide, that are yellow-green ripening to red.
The edible fruits are used for cider, jams and jellies. Fruit yield is up to 30 pounds per tree
The orange-brown, scaly bark cracks into plates on older trees.
Hardy zone 3 to 9. It is more heat tolerant than most of the Sorbus(s).

* photos taken by Milan Havlis, owner of central Europe's premier plant nursery

* historical archive photo

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id39567/

Sorbus esserteauiana ( Esserts Sorbus )
A rounded medium size tree native to western Sichuan in southwest China. Some records include: 30 years - 40 feet; largest on record - 50 x 35 feet with a trunk diameter of 1 foot.
The pinnate leaves, up to 12 inches in length are composed of up to 15 toothed, taper pointed leaflets up to 4 x 1.5 inches.
The foliage is deep red-purple at first turning to glossy deep green above, downy gray beneath; turning to attractive red during autumn.
The white flowers, up to 0.25 inches wide are borne in flat clusters up to 6 inches across during late spring.
They are followed by scarlet-red berries, up to 0.3 inches wide, that persist into winter. The berries are borne in dense, wide clusters.
The gray-brown bark is thin and scaly.
Hardy zone 5 to 8 ( possibly 4 as it has reached 15 feet at Dominion Arboretum in Ottawa, Canada ). Easy to grown.

'Winter Cheer'
Exceptionally persistant berries last until February.

Sorbus fennica
A small tree native to Scotland. The largest on record is 40 x 40 feet.
The simple oblong leaves are up to 6 inches in length.
The fruits are red.
Hardy north to zone 5

Sorbus folgneri ( Folgner's Whitebeam )
A moderate growing small tree reaching around 25 x 25 feet that is native to central China. Some records include: fastest recorded growth rate - 2 feet; 23 years - 32 feet with a trunk diameter of 14 inches; largest on record - 66 x 25 feet with a trunk diameter of 26 inches.
The attractive pinnate leaves, up to 4 inches in length are composed of toothed, lance-shaped leaflets. The foliage is bright green above, metallic silver beneath; turning to brilliant scarlet-red in autumn.
The creamy-white flowers are borne in clusters up to 4 inches across.
They are followed by heavy clusters of deep red berries up to 0.5 inches across.
Hardy zones 4b to 7, it is hardier than originally estimated, having survived at Dominion Arboretum in Ottawa, Canada. An excellent street tree it can tolerate drought and wind as well as pollution.

Sorbus forrestii ( Forrest Sorbus )
A moderate growing, wide spreading, domed small tree native to southwest China that is very similar to Sorbus hupehensis but with very large fruit.
Some records include: fastest recorded growth rate - 2 feet; 5 years - 10 x 7 feet; 20 years - 20 feet; largest on record - 40 x 33 feet.
The pinnate leaves, up to 8 inches in length are composed of up to 17 oblong leaflets up to 2 x 0.5 inches in size.
The foliage is blue-green above, gray-green beneath.
The flower, up to 0.5 inches wide, are borne flattened clusters are up to 4 inches across in mid spring.
The berries, up to 0.5 inches are nearly pure white when ripe and are not attractive to birds, thus often remaining into March.
The smooth, purple-gray bark becomes shallowly vertically fissured with age.
Zone 7 to 9 tolerating as low as -4 F

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id1076787/

Sorbus fruticosa
A multistemmed, shrubby dwarf shrub reaching up to 3.3 feet in 15 years, eventually to 5 x 10 feet. It often suckers forming a small thicket but if these are removed it may be trained as a small tree.
The delicate pinnate foliage is narrow and turns red in autumn contrasting
The berries are white.
Very tough and easy to grow.

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id868310/

Sorbus 'Ghose'
A new undescribed species from northeast India reaching a maximum height of 100 feet.
Some records include: 23 years - 30 feet with a trunk diameter of 16 inches.
The pinnate leaves, up to 13 inches in length are composed of up to 15 toothed leaflets up to 4 x 1 inches. The foliage is deep green above, silvery to tan beneath.
The white flowers are borne in large clusters and are followed by crimson-red ( pink at first ) berries.
The thick stiff twigs bear dark red buds up to 1.3 inches.
Hardy north to zone 7 tolerating as low as -4 F

Sorbus glabrescens ( White Fruited Rowan )
A medium size tree native to Yunnan Province in China that reaches a maximum size of 50 feet.
The pinnate leaves, up to 10.5 inches in length are composed of up to 17 finely serrated, oval leaflets up to 2.3 x 0.8 inches. The foliage is blue-green turning to orange and red very late in autumn.'
The creamy-white flowers are borne in clusters up to 6 inches across in late spring.
They are followed by very ornamental white berries.
The bark is dark gray and the shoots are stout.

Sorbus graeca ( Pannonian Mountain Ash )
An arching, broad-spreading, deciduous, large shrub to small tree, reaching up to 27 feet, that is native to the Valley of Dyje ( Thaya ) in southwest Moravia & neighboring parts of Austria. It belongs to the Whitebeam section of the Sorbus genus. It is closely related to Sorbus umbellata.
The double-toothed, broadly-oval to rounded leaves are up to 3.5 inches in length. The leathery foliage is glossy mid-green above and white woolly beneath.
The red berries are up to 0.5 inches wide.
Little is known about it in cultivation but it is likely more heat and drought tolerant than most other species.

* excellent photo link below
http://www.biopix.com/sorbus-graeca_photo-59281.aspx

Sorbus hedlundii
A very attractive medium-size tree native to the Himalayas that is very similar to Sorbus vestita though with prominent veins and silvery undersides on the leaves. Some records include: 20 years - ; largest on record - 70 x 30 feet with a trunk diameter of 17 inches.
The bark is beige.
Hardy zone 8 to 10. Tough and easy to grow.

Sorbus hemsleyi
A very handsome, dense and lush, moderate growing, upright, medium size tree native to China. Some records include: fastest recorded growth rate - 32 inches; 28 years - 27 x 27 feet with a trunk diameter of 14 inches; largest on record - likely 50 + feet. It was introduced into Great Britain as late as 1992.
The leaves are simple, narrow, deep green above and white beneath. The foliage in many ways resembles our native Whitebeam but is narrower and curled, showing the bright white underside well. The new leaves are even whiter, having a layer of hairs on the upper side, and the autumn colour is a rich butter yellow. Makes a small to medium sized upright tree.

Sorbus x hostii
A shrub reaching up to 15 x 10 feet that is the hybrid between Sorbus chamaemespilus & S. mougeotii.
Some records include: 27 years - 33 feet with a trunk diameter of 9.5 inches; largest on record - unknown.
It is very similar to Sorbus mougeotii except its leaves are sharper toothed and a little longer, up to 5 inches in length.
The flowers are pink borne in clusters up to 6 inches across and resemble that of Sorbus chamaemespilus.
They are followed by red fruits.
Hardy zone 5 to 9

Sorbus hupehensis ( Hubei Mountain Ash )
A vigorous, dense, upright, medium-size tree native to western and central China. Some records include: fastest recorded growth rate - 4 feet; 5 years - 12 x 7 feet; 20 years - 50 x 20 feet; largest on record - 60 x 40 feet with a trunk diameter of 2 feet.
The pinnate leaves, up to 10 inches in length are composed of 11 to 17 thick, lightly-toothed, oblong leaflets up to 3 x 1 inches in size. The smooth foliage is blue-green above, blue-gray beneath; turning to intense scarlet-red during autumn.
The white flowers, up to 0.25 inches wide are borne in clusters up to 6 inches wide, during late spring.
They are followed by persistent white berries, up to 0.35 inches wide that have pink flushing at the top when ripe. The fruit stalks are intense rose-pink and often persist into late winter even after the berries have dropped.
The branches are purplish. The bark is smooth and gray.
Hardy zone 2 to 8 in full sun to partial shade. It is moderately drought and salt tolerant. Hubei Mountain Ash is among the best Mountain Ash for the midwestern U.S. including the Chicago area.

* photos taken on July 26 2015 @ Niagara Parks Bot. Gardens, Niagara Falls, ON


* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id775215/

'Coral Fire'
Foliage turns red in autumn. The fruits are pinkish-red and the bark is also red.

'Obtusa'
Pink fruits

Sorbus x hybrida
A medium-sized tree native to Scandinavia. Some records include: fastest recorded growth rate - 3 feet; 20 years - 60 x 40 feet with a trunk diameter of 2.5 feet.
The basal-lobed, elliptic leaves, are up to 5 x 2.3 inches in size. The foliage is deep green above, silver felted beneath. The foliage turns to yellow and orange during autumn.
The white flowers, to 0.5 inches wide are borne in dense clusters up to 5 inches across in late spring.
They are followed by small rounded deep red berries, up to 0.8 inches wide.
The bark is gray.
Hardy zone 2b to 7

* historical archive photo


Sorbus insignis
A large tree native to Sikkim in the Himalayas. Some records include: 20 years - 20 feet; largest on record - 66 x 20 feet with a trunk diameter of 38 inches. It is one of the most beautiful of all Sorbus's.
The pinnate leaves, up to 12 inches in length are composed of up to 13 shallow toothed leaflets up to 8 x 3 inches. The foliage is glossy deep green, turning stunning glossy red in autumn.
The white flowers are borne in clusters.
They are followed by pink berries that persist all winter.
Hardy zone 7 to 9. In North America, it thrives only in the Pacific Northwest and if soil is consistently moist during summer.

'Harrowiana'
A small conical tree. Some records include: 20 years - 23 feet; largest on record - 45 feet.
The pinnate leaves, up to 12 inches in length are composed of up to 11 shallow toothed leaflets up to 7 x 2 inches. The foliage is smooth and green above, grayish beneath.
The small fruits are deep pink to scarlet-red.

Sorbus intermedia ( Swedish Whitebeam )
A rare fast growing, dense, domed, medium-sized tree native to the Baltics and Scandinavia regions of northern Europe. Some records include: fastest recorded growth rate - 3 feet; 20 years - 60 x 40 feet; largest on record - 75 x 70 feet with a trunk diameter of 3.6 feet. Moderately long-lived, it is known to persist up to 134 years, possibly longer.
The simple, leathery oval leaves, up to 5 x 3 inches in size, with small basal lobes are glossy deep green above, white hairy beneath. The foliage turns to yellow during autumn, though reports from Alberta, Canada indicate excellent red fall color.
The small white flowers, up to 0.75 inches wide are borne in dense heads up to 5 inches across during late spring.
They are followed in late summer by broadly-oval, scarlet-red, edible berries up to an inch in length.
The lightly fissured bark is gray. The young stems are felted.
Hardy zone 3 to 8, it thrives in some of the most hostile climates conditions in northern Europe ( even the Shetland Islands ) where it makes a great shelterbelt and street tree. Disease resistant and also wind, drought, urban & pollution tolerant.


* photos taken on July 26 2015 @ Niagara Parks Bot. Gardens, Niagara Falls, ON

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id39572/

Sorbus japonica
An medium-size tree native to Korea and Japan.
Some records include: 20 years - 47 feet; largest on record - 70 feet.
The simple, shallowly-lobed, ovate leaves, up to 5 inches in length are deep green above and white-felted beneath. The foliage turns to yellow in autumn.
The flowers are creamy-white. They are followed by scarlet-red fruits up to 0.5 inches wide.
The twigs are downy.
Hardy zones 6 to 8.

Sorbus 'Joseph Rock'
A vigorous upright, broadly-conical small tree. Some records include: fastest recorded growth rate - 3 feet; 15 years - 25 feet; 20 years - 40 x 20 feet; largest on record - 50 x 50 feet with a trunk diameter of 16 inches.
The pinnate leaves, up to 10 inches are composed of 15 to 21 sharply-toothed, narrow leaflets up to 1.5 x 0.5 inches. The foliage is glossy bright green above, gray-green below; turning intense orange to purple-red in autumn.
The white flowers, to 0.5 inches wide are borne in flattened clusters up to 4 inches across in late spring.
The persistant fruits, borne on red stalks, are up to 0.5 inches wide are cream at first, ripening to orange-yellow.
The nearly smooth gray bark has small orangish lenticels.
Hardy zones 4 to 9

Sorbus keissleri
A rare, medium-sized, deciduous tree, reaching a maximum height of 50 feet, that is native to mountain forests in western and central China. Some records include: 20 years - 20 feet. This beautiful tree deserves much wider use in cultivation.
The toothed, simple, obovate leaves are up to 4.2 x 2.5 inches in size. The very attractive foliage is glossy deep green above, silvery or pale green beneath. The leaves turn to golden-yellow to red during autumn.
The creamy-white flowers are borne on clusters up to 2 inches across, during late spring into early summer.
They are followed by brownish-green to red fruits, up to 0.5 x 0.3 inches in size, during late summer into early autumn.
Hardy zones 6 to 7 in full sun.

Sorbus x kewensis
A massive, heavy set, round headed medium size tree that is the hybrid between Sorbus aucuparia & S. pohuashanensis.
Some records include: 20 years - 27 x 20 feet; largest on record - 90 x 60 feet with a trunk diameter of 3 feet.
The pinnate leaves, up to 12 inches in length are composed of up to 19 to 23 sharply toothed, oblong leaflets. The foliage is rich green above, light gray felted beneath; turning to purple-red during autumn.
The creamy-white flowers are borne in large clusters.
They are followed by bright orange-red berries in very large heavy clusters in autumn.
The gray bark is smooth and beech-like.
Hardy zone 4 to 9

Sorbus koehneana ( White Fruited Chinese Rowan )
A moderate growing, multi-stemmed large shrub native to central China that can reach over 10 x 10 feet. Largest on record - 17 x 13 feet with a trunk diameter of 8 inches.
The pinnate leaves are composed of 17 to 25 sharply-toothed, oblong leaflets, up to 1.5 inches long. The foliage is deep green during spring and summer turning to plum purple during autumn.
The white flowers, up to 0.3 inches wide, are borne in clusters, up to 3 inches wide.
They are followed by large clusters of white berries.
Hardy zones 4b to 7, it thrives at Dominion Arboretum in Ottawa, Canada but is otherwise virtually unknown in cultivation in North America. Grows in sun or shade, and is in fact the best Sorbus for shade.

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id276202/

Sorbus lanceifolia
A deciduous, large shrub, reaching a maximum height of 13 feet, that is native to the arctic border of Norway. Some records include: 20 years - 10 feet.
The attractive, deeply-lobed, narrowly-ovate leaves are deep green.
The white flowers are followed by clusters of 0.4 inch scarlet-red berries.
Hardy zones 2 to 5.

Sorbus lanata ( Hairy Rowan )
Similar to Sorbus aria ( reaching up to 80 feet ) but native to the Himalayas ( Afghanistan to Nepal ) and vigorous with larger leaves, up to 9 x 4 inches.
The large elliptic leaves have toothed and shallow acute lobes.
The leaves are smooth green above, gray-white woolly beneath.
The fragrant white flowers up to 0.5 inches across are borne in clusters in late spring. They are followed by yellowish-red edible fruit.
Hardy zone 6 to 8

Sorbus latifolia ( Service Tree )
A very vigorous, broadly-columnar, medium-sized tree native to western & central Europe. Very old trees become massive and dome shaped resembling the Oak in appearance.
Some records include: fastest recorded growth rate - 4 feet; largest on record - 75 x 30 feet with a trunk diameter of 3.6 feet.
The simple, sharply double-toothed, broadly-oval leaves, up to 5 x 3 inches with small basal lobes are smooth glossy deep green above, downy gray below. The foliage turns to yellow during autumn.
The small white flowers, up to 0.5 inches wide are borne in flattened heads up to 4 inches across in late spring.
They are followed in late summer by rounded, yellow-brown, up to 0.5 inches wide. The fruits are edible.
The dark gray bark is flaking and cracked.
Hardy zone 4 to 8 tolerating as low as -30 F. Breeds true from seed.

Sorbus megalocarpa ( Large Fruited Whitebeam )
A very striking small tree native to China.
Some records include: 17 years - 20 feet with a trunk diameter of 6 inches; largest on record - 55 x 30 feet.
The simple, very large, obovate leaves, up to 10 x 5 inches have wavy to shallowly toothed margins.
The foliage is reddish at first turning deep green turning to scarlet-red in autumn.
The creamy-white flowers are borne in dense clusters up to 6 inches across. Unusual for Sorbus, they appear early in spring before the foliage.
They are followed by very large, rusty-brown fruits up to 0.4 inches across.
Hardy zone 4 to 9

Sorbus meliosmifolia
An upright, small tree native to western China.
Some records include: 20 years - 20 feet; 30 years - 28 feet with a basal trunk diameter of 28 inches; largest on record - 36 feet
The deeply double-toothed, elliptic leaves, up to 7 x 4 inches, are coppery at first, turning to deep green. The foliage turns to attractive yellow, orange and red during autumn.
They appear early in spring and last late in autumn. The foliage can tolerate as low as 20 F with no damage.
The white flowers are borne in clusters up to 4 inches across.
They are followed by deep reddish-brown berries up to 0.5 inches wide. The stems are purplish-brown.
Hardy north to zone 6.

Sorbus microphylla
A small tree native to the Himalayas. Some records include: 19 years - 17 feet with a trunk diameter of 3.5 inches; largest on record - 30 x 10 feet with a trunk diameter of 1 foot.
The pinnate leaves are composed of up to 30 deeply toothed leaflets up to 1.5 inches in length.
Hardy to zone 8.

Sorbus minima ( Lesser Whitebeam )
An attractive, medium-sized, deciduous shrub, reaching a maximum height of 10 feet, that is native to Wales in the British Isles where it is endangered. It can be found in cultivation in North America at Dawes Arboretum in Ohio.
The narrow-oblong leaves are dull green above, gray downy beneath.
The showy, creamy-white flowers are borne on clusters during late spring.
They are followed by scarlet-red fruit, up to 0.3 inches wide.
Hardy zones 5 to 7 ( also 8 in maritime climates ). It is lime tolerant.

Sorbus mougeotii
A very attractive, dense medium-size tree native to the Alps and Pyrenee Mountain Ranges in central Europe. Some records include: 20 years - 27 feet; largest on record - 66 feet with a trunk diameter of 20 inches.
The simple, broad, shallow-lobed, ovate leaves are up to 5 x 4 inches in size. The foliage is glossy deep green above and densely downy white beneath.
The creamy-white flowers, up to 0.3 inches wide, are borne in small heads during late spring.
They are followed by small fruits up to 0.25 inches that are green ripening to red. They ripen during early autumn.
The bark is gray
Hardy zone 5 to 8. Urban and clay tolerant; it tolerates cool summers, even thriving in the Faroe Islands.

Sorbus oligodonta ( Kite Leaf Rowan )
Previously considered a subspecies of Sorbus hupehensis.
A dense, medium size, vigorous tree native to western and central China as well as Burma.
Some records include: fastest recorded growth rate - 4 feet; 5 years - 12 x 7 feet; 20 years - 50 x 20 feet; largest on record - 60 x 40 feet with a trunk diameter of 2 feet.
The pinnate leaves, up to 7 inches in length are composed of up to 17 thick, lightly toothed rounded leaflets up to 1.7 x 0.8 inches in size. The smooth foliage is blue-green above, blue-gray beneath and turns intense scarlet-red in autumn.
The white flowers, up to 0.25 inches wide are borne in clusters up to 6 inches wide in late spring.
They are followed by persistant pearly white berries, up to 0.35 inches wide that are borne in heavy clusters.
The branches are purplish. The bark is smooth and dark gray.
Hardy zone 5 to 8, moderately drought and salt tolerant.


Sorbus pallescens
A vigorous, upright, leafy, massive, dome shaped, medium size tree native to China.
Some records include: 20 years - ; 50 years - 47 x 50 feet with a trunk diameter of 2.5 feet; largest on record - 55 feet ( larger trees most likely exist but have not been measured ).
The simple, double serrated, elliptic leaves are up to 3 x 2 inches in size.
The foliage is bronze at first then turning to green above, white felted beneath and persisting late in autumn.
The creamy-white flowers are borne in heads up to 3 inches across.
They are followed by fruits that are green ripening to red.
The bark is flaking.
Hardy zone 5 to 9

Sorbus persica ( Persian Mountain Ash )
A very attractive, broad-crowned, small, deciduous tree, reaching up to 17 x 17 feet, that is native to central Asia ( Kazakhstan, Kyrgyzstan and Uzbekistan; south to Iran to Afghanistan. It is very scattered in distribution and endangered in its natural range. This tree has great potential in forest reclamation in dry upland climates and also for use in breeding more drought tolerant Mountain Ashes. It can live up to 100 years in age.
The deeply-toothed, elliptical leaves are up to 4 x 2.4 inches in size. The leathery foliage is glossy bright green above, white beneath.
The white flowers are borne on dense clusters, up to 3.5 inches across, during late spring.
They are followed by edible fruits.
Hardy zones 4 to 7 ( est ) in full sun on very well drained soil. It is very pest and disease resistant and also more heat / drought tolerant than other species of Sorbus.

Sorbus pohuashanensis ( Pohua Mountain Ash )
A upright, round headed, medium-sized tree native to mountains of northern China that is a close relative of Sorbus aucuparia. Some records include: fastest recorded growth rate - 3 + feet; 15 years - 25 feet ( Ottawa, Canada ); 20 years - 30 feet; largest on record - 70 x 40 feet with a trunk diameter of 1.5 feet.
The leaves, up to 8 inches in length are composed of up to 15 oblong leaflets up to 2.5 inches in length. The foliage is deep green above and blue-felted beneath; turning to scarlet-red in autumn.
The creamy-white flowers are borne in woolly clusters up to 5 inches across during late spring.
They are followed by abundant, showy, orange-red to red fruits, up to 0.3 inches wide.
Hardy zone 4 to 8 ( seed source from Liaoning & Nei Mongol Provinces could be as hardy as 3 or even 2 )

Sorbus poteriifolia ( Pygmy Sorbus )
Also called Sorbus pygmaea, is a dwarf suckering shrub, reaching up to 4 x 12 inches in 10 years, eventually slightly more. Some records include: largest on record - 9 feet. It makes a great plant for the rock garden. It is native to northwestern Yunnan Province in China as well as northern Burma.
The pinnate leaves, up to 4 inches long, are composed of 9 to 19 sharply-toothed, oblong leaflets up to 0.8 x 0.3 inches in size. The deep green foliage turns to scarlet-red during autumn.
The pink flowers, up to 0.3 inches wide, are borne in clusters during late spring.
They are followed by white or sometimes pink tinged berries, up to 0.3 inches wide, during autumn.
Hardy zones 5 to 7 in full sun to partial shade, preferring moist, peaty soil.
It is unreliable in cultivation in most places, tending only to thrive in Scotland and the far north of England in Europe and the British Columbia to Alaska coast in North America, disliking hot dry summers.

Sorbus prattii
A moderate growing, dome shaped small tree native to western China.
Some records include: 20 years - ; largest on record - 30 x 20 feet with a trunk diameter of 13 inches.
The leaves, up to 7.5 inches in length are composed of up to 27 leaflets up to 1.5 inches in length. The foliage is deep green above, downy glaucous blue beneath.
The creamy white flowers are borne in downy heads up to 3 inches across.
They are followed by white berries up to 0.4 inches across.
Hardy zone 6 to 8. Lime tolerant.

Sorbus pseudofennica ( Arran Service Tree )
A very rare, attractive, upright, oval tree that is native to northwestern Europe and resembles Sorbus domestica. It is considered by some to be the hybrid between Sorbus arranensis & aucuparia. It's entire population of around 500 trees survives on the Scotish Isle of Arran growing on a stream bank in Glen Diomhan Reserve.
Some records include: 20 years - ; 26 years - 37 feet with a trunk diameter of 14.5 inches; largest on record - 50 x 30 feet. In North America; it can be found in cultivation at Dawes Arboretum in Ohio.
The toothed to lobed, oval leaves are up to 3 inches in length. The very attractive foliage is glossy mid-green above, white beneath; turning to scarlet-red during autumn.
Hardy zone 5 to 9

* excellent photo link found on internet
http://www.arkive.org/arran-service-tree/sorbus-pseudofennica/

Sorbus randaiensis ( Taiwan Sorbus )
A small tree native to high mountains in Taiwan, it is closely related to Sorbus commixta. Some records include: 20 years - ; 27 years - 20 feet with a trunk diameter of 1 foot; largest on record - 27 x 10 feet.
The leaves, up to 7 inches in length are composed of up to 21 sharply toothed, taper pointed leaflets up to 1.7 x 0.5 inches. The foliage is green above, downy gray beneath and turns to scarlet-orange in autumn.
The foliage appears very early ( late February in England ) and seems impervious to late spring frosts.
The white flowers are borne in terminal cluster up to 3.2 inches across in spring.
They are followed by tiny red fruits.
The buds are sticky in late winter before opening.
Hardy zone 7 to 10

Sorbus reducta ( Dwarf Chinese Mountain Ash )
A miniature Mountain Ash native to southwestern China and mountains of Burma which forms a moderate growing, suckering, low spreading shrub.
Some records include: 5 years - 3.5 x 8 feet; 20 years - 5 x 6 feet; largest on record - 5 x 8 feet. On light loamy soils, it can spread to cover large areas.
The fine pinnate leaves, up to 4.3 inches in length are composed of up to 15 deeply toothed leaflets up to an 1.3 inches in length.
The reddish stalked foliage is glossy deep green turning to rich red-purple in autumn.
The creamy-white flowers are borne in clusters up to inches across
They are followed by small, pink to deep red berries which persist into December.
The young stems are lightly bristly.
Hardy zone 3 to 8 in full sun to partial shade. Prefers fertile, moist soil. Great for using in rock gardens or mixing with dwarf conifers and heathers.

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id511342/

Sorbus rupicola ( Rock Whitebeam )
A rare small tree reaching a maximum height of 17 feet that is native to the British Isles, Norway, Sweden and Russsia. It is often found in the wild growing out of cracks in limestone.
The simple, double-toothed, oblong leaves are up to 5.5 inches in length. The foliage is deep green above, intensely silvery-white woolly beneath.
It bears scarlet-red berries, up to 0.6 inches wide, during autumn.
Hardy zones 5 to 7.

* photo of unknown internet source



Sorbus sargentiana ( Sargent's Rowan )
A beautiful, open medium-sized tree native to western China. Some records include: fastest recorded growth rate - 3 feet; 20 years - 50 x 20 feet; largest on record - 50 x 33 feet with a trunk diameter of 1.7 feet.
The pinnate leaves, up to 16 inches in length are composed of 9 to 13 lightly-serrated, taper-pointed, oblong leaflets up to 6 x 2 ( rarely over 3 ) inches. The foliage is reddish at first turning to bright green in spring turning in summer to glossy deep green above, gray-green and somewhat downy beneath. In autumn the foliage turns brilliant glowing orange-red. The fall color is among the best of all trees.
The creamy-white flowers, up to 0.25 inches wide are borne in clusters up to 10 inches across in early summer.
They are followed by 0.25 inch showy glossy scarlet-red berries in very large, dense clusters, lasting into early winter.
The purple-brown bark cracks and flakes with age.
The branches are stout and heavy set, with large, sticky, deep red winter buds.
Hardy zone 5 to 8

* photo of unknown internet source


Sorbus scalaris ( Ladder Rowan )
A flat-crowned small tree with long arching branches that is native to western China. Some records include: fastest recorded growth rate - 2 feet; 20 years - 40 x 20 feet; largest on record - 40 x 33 feet with a trunk diameter of 2 feet.
The ferny pinnate leaves, up to 8 inches in length are composed of 23 to 37 sparsely toothed narrow oblong leaflets up to 1.5 x 0.5 inches. The ferny foliage is glossy deep green above, pale gray felted beneath, turning deep red to purple late in autumn.
The downy white flowers, up to 0.25 inches wide are borne in flattened clusters up to 8 inches across in late spring.
They are replaced by tiny scarlet-red fruits up to 0.25 inches wide in large, dense clusters.
The smooth gray bark develops shallow fissures on older trees.
Hardy zone 4 to 8, it thrives at Dominion Arboretum in Ottawa, Canada but is generally rarely seen in North America.

Sorbus scopulina ( Greene Mountain Ash )
A moderate growing shrub to small tree native to the Rocky and Cascade mountains in western North America ( from near Kotzebue, Alaska to Fairbanks, Alaska to southwest Northwest Territories to northwest Saskatchewan; south to central California to northwest New Mexico to western South Dakota ). Some records include: 5 years - 10 x 3.5 feet; largest on record - 20 x 20 feet with a trunk diameter of 8 inches. It often suckers to form a thicket.
The leaves, up to 10 inches in length are composed of 9 to 15 toothed narrow leaflets up to 5 x 1 inches in size. The luxuriant glossy deep green foliage turns to orange & scarlet-red during autumn.
The fragrant, creamy-white flowers, up to 0.4 inches wide, are borne in clusters up to 6 inches across.
They are followed by glossy scarlet-red berries, up to 0.4 inches across. They are borne on clusters that persist into winter.
The smooth bark is reddish-gray.
Hardy north to zone 3 ( hardiest seed source likely zone 2, even 1 for central Alaskan native sources ) growing in climates with 20 inches or more of annual precip.
It is very tolerant of pollution and is disease resistant. Requires acidic to neutral soil.

* photo taken on August 3 2010 @ University of Guelph Arboretum, Ontario

* photo of unknown internet source

* photo taken by http://www.nwplants.com

* historical archive photo

* U.S. Geological Survey map

* photos taken by Jean Pawek @ CalPhotos


Sorbus sitchensis ( Sitka Mountain Ash )
A rounded, small tree reaching up to 30 x 10 feet that is native to western North America ( from Kodiak, Alaska to far southern Yukon to Dawson Creek, British Columbia to Banff National Park, Alberta; south to northern California to central Idaho to northwest Montana ). Some records include: largest on record - 50 x 20 feet. It makes a beautiful patio or lawn tree.
The pinnate leaves, up to 8 inches in length are composed of 7 to 11 ( rarely 13 ) oblong leaflets up to 3 inches in length. The attractive foliage is deep blue-green, turning to yellow or purple during autumn.
The creamy-white flowers are borne in clusters up to 8 ( rarely over 4 ) inches across.
They are followed by showy clusters of glossy bright orange-scarlet berries up to 0.5 inches across. The berries average double the size of Sorbus americana.
The reddish bark is smooth.
Hardy zone 2 to 6 in full sun to partial shade on moist, fertile soil. The Sitka Mountain Ash absolutely hates hot summers, especially where hot humid nights occur.

* photo taken by http://www.nwplants.com

* historical archive photo


Sorbus subcuneata
A small tree native to the British Isles where it is endangered.
Some records include: largest on record - 47 feet with a trunk diameter of 11 inches

Sorbus takhtajanii
Also called Sorbus persica acutilobata. A rare, deciduous, dense, rounded, large shrub or small tree, reaching a maximum height of 23 feet, that is native to western Asia from Turkey to the Caspian Sea. Some records include: 20 years - 17 feet.
The deeply-toothed to shallowly-lobed, elliptical leaves are silvery at first, turning to glossy deep green above, silvery-white beneath. The very attractive foliage deserves this tree much wider use.
The creamy-white flowers are borne on flat-topped clusters.
Hardy zones 6 to 8.

Sorbus thibetica ( Tibetan Sorbus )
A rare, very fast growing, large, conical to broad crowned tree native to the Himalayas and southwest China. Some records include: fastest recorded growth rate - 4 feet; 20 years - 60 x 40 feet; 40 years - 80 feet; largest on record - 100 x 50 feet. The Tibetan Sorbus is long lived and among the most beautiful of all Sorbus.
The simple, sharply-toothed, rounded leaves, up to 10 x 8 inches, are deep green above and white felted beneath.
The white flowers, to 0.5 inches wide are borne in clusters up to 2.5 inches across in late spring.
They are followed by small rounded orange-red berries, up to 0.5 inches wide.
The scaly, thin, gray-brown bark is cracked; flaking at the base on older trees.
Hardy zone 5 to 8

'John Mitchell'
Very similar but more vigorous. Some records include: 20 years - 60 x 40 feet; 32 years - trunk diameter of 16.5 inches; 40 years - 80 feet; largest on record - 100 x 50 feet with a trunk diameter of 2 + feet.
Propagation is from softwood cuttings taken in summer.

Sorbus x thuringiaca ( Oakleaf Mountain Ash )
A dense, medium-size tree that is the hybrid between Sorbus aria & S. aucuparia. Some records include: fastest recorded growth rate - 3 feet; 23 years - 20 x 10 feet; largest on record - 90 x 35 feet with a trunk diameter of 3 feet.
The deeply lobed and toothed, elliptic leaves, up to 8 x 4 inches.
The leathery foliage is glossy deep green above, hairy white beneath; turning to orange-scarlet in autumn.
The white flowers, to 0.5 inches wide are borne in dense clusters up to 5 inches across in late spring.
They are followed by small, rounded, shiny scarlet-red berries, up to 0.5 inches wide.
The bark is light-gray and smooth on young trees, cracked and flaking on older trees.
Hardy zone 3 to 7. It does not breed true from seed.

* photos taken on Aug 1 2013 in Goderich, Ontario


'Fastigiata'
Strongly upright growth habit.
Very deep green summer foliage.

'Pinnatifida'



Sorbus tianschanica ( Tien-Shan Mountain Ash )
A broad-crownded, small tree similar to Sorbus aucuparia but is native to central Asia. Some records include: fastest recorded growth rate - 2 feet; 10 years - 16 x 8.5 feet; 20 years - 17 feet with a trunk diameter of 9 inches; largest on record - 25 x 20 feet.
The pinnate leaves, up to 9 inches in length, are composed of up to 15 leaflets up to 3 x 0.6 inches in size. The glossy deep green foliage colors well late in autumn.
The flower clusters, up to 0.8 inches wide are borne in dense clusters up to 6 inches in width.
They are followed by deep red berries, up to 0.5 inches wide, during autumn.
Hardy zones 2 to 6; it even thrives in Manitoba and Saskatchewan.
This tree prefers cold winters and hot summers and grows poorly in maritime climates.

Sorbus torminalis ( Wild Service Tree )
A rare, handsome, massive, heavy-set, rounded ( pyramidal at first ), medium-size tree native from central & southern Europe to western Asia; south to northern Africa. Some records include: fastest recorded growth rate - 3 feet; 10 years - 26 feet; 20 years - 40 x 20 feet; largest on record - 114 x 50 feet with a trunk diameter of 5 feet; longest lived - 300 years.
The simple, toothed, sharply-lobed, broadly-ovate leaves, are up to 6 x 4 inches in size. The foliage is bright green and downy at first, turning to glossy deep green above, light green beneath; turning to deep red during autumn.
The flowers, to 0.5 inches wide are borne in open flattened clusters up to 5 inches across during late spring.
They are followed by fruits, up to 0.5 inches wide that are olive speckled with brown. The fruits are edible and are good in drinks.
The bark is smooth and deep brown in young trees; later becoming furrowed and plated.
The timber is of high quality though it is rarely grown for such.
Hardy zone 4 to 7. Very heat and clay tolerant. Clones from Ukraine are more drought tolerant. Wild Service Tree is among the best Sorbus for the midwestern U.S. including the Chicago area.

* historical archive photo

* excellent photo link found on internet
http://www.biolib.cz/en/taxon/id39576/

Sorbus turkestanica ( Turkestan Mountain Ash )
A deciduous, small tree that is part of the Whitebeam division of the Sorbus genus. It was formerly widespread in central Asia but is now endangered and restricted to Tajikistan.

Sorbus umbellata
A shrubby, small tree, that is very similar to Sorbus aria but reaches a maximum height of only 23 feet and is native from much of southeastern Europe to central Asia ( Turkmenistan ): south to Turkey, Lebanon and Iran. Some records include: 20 years - 17 feet.
The deeply double-toothed broad-oval to rounded leaves are up to 2.8 ( rarely over 2 ) inches in length. The foliage is deep green above, silvery-white woolly beneath.
The creamy-white flowers, up to 0.6 inches wide, are borne on flat clusters.
They are followed by orangish-red berries up to 0.6 inches wide.
Hardy zones 5 to 8. It is likely more drought tolerant than most species of Sorbus.

Sorbus vestita ( Himalayan Whitebeam )
A rare pyramidal medium size tree native to forests in the Himalayas that is among the handsomest of all hardy trees. Some records include: fastest recorded growth rate - 4 feet; 20 years - 30 feet; largest on record - 80 x 40 feet with a trunk diameter of 38 inches.
The Himalayans Whitebeam is long lived and can easily exceed 100 years.
The sharply-toothed, elliptical leaves are up to 10 x 6 inches in size.
The leathery foliage is white hairy at first turning to glossy deep green above, densely white hairy beneath.
The creamy-white flowers up to an inch across are borne in flattened clusters up to 4 inches across in late spring.
They are followed by orange-red rounded berries up to an inch across.
The light gray bark peels in thick flakes.
Hardy zones 6 to 8. Propagationis from seed in autumn or softwood cuttings taken in summer.

Sorbus vexans ( Bloody Whitebeam )
A deciduous, large shrub to small tree, reaching a maximum height of 20 feet. It is native to north Devon in England where it is endangered due to its low numbers and tiny natural range. There are barely more than a hundred Bloody Whitebeams left in the world.
The toothed, ovate leaves are glossy deep green above, white beneath.
The creamy-white flowers are followed by red berries, up to 0.6 inches in size, that are borne on clusters.
Hardy zones 6 to 8, it prefers acidic soils unlike most Sorbus.

* excellent photo link found on internet
http://www.arkive.org/whitebeam/sorbus-vexans/

Sorbus vilmorinii ( Vilmore Sorbus )
A moderate to vigorous growing, delicate, open, small, broadly spreading, long lived tree that is native to mountain woods in western China. Some records include: fastest recorded growth rate - 2 feet; 26 years - 40 feet with a trunk diameter of 9 inches; largest on record - 47 x 20 feet with a trunk diameter of 1.5 feet.
The ferny pinnate leaves, up to 7 inches in length are composed of 19 to 31 serrate-edged, oblong leaflets up to 1 inch in length. The foliage is glossy deep green above and gray-green beneath. The foliage turns red to purple late in autumn.
The flowers, up to 0.25 inches wide are borne in loose open clusters up to 4 inches across in late spring.
They are followed by fruits, up to 0.5 inches wide that are red at first, ripening to white.
The bark is smooth and dark brown.
Hardy zone 5 to 8. Propagation is either from seed or softwood cuttings taken in summer.

'Pearly King'
Larger fruits and excellent fall color.

Sorbus xanthoneura
A small tree native to China.
Some records include: fastest recorded growth rate - 2 feet; 20 years - 20 feet; largest on record - 27 feet.
The simple, double-toothed, elliptic leaves, up to 5.5 x 2 inches are white beneath.
The red berries are up to 0.3 inches wide.
The bark is furrowed and medium gray.
Hardy north to zone 6. Heat tolerant and thrives in the Mid Atlantic.

Sorbus wardii ( Tibetan Whitebeam )
A fast growing rounded tree reaching up to 32 x 26 feet in 20 years. It is native to Bhutan and Tibet. Some records include: largest on record - 50 x 25 feet with a trunk diameter of 14 inches.
The simple, toothed, broad-oval, silvery-gray foliage looks amazing against a dark background.
The creamy-white flowers are followed by amber-yellow berries up to 0.5 inches wide.
Hardy zones 6 to 9 ( est )

Sorbus wilsoniana
A small, sturdy tree native to central China.
Some records include: 20 years - ; largest on record - 33 x 20 feet.
The pinnate leaves, up to 10 inches in length are composed of up to 15 lance shaped leaflets that are up to 3.5 x 1 inch in size.
The foliage is green above and gray-green beneath.
The creamy-white flowers are borne in clusters up to 6 inches across.
They are followed by rounded carmine berries.
The buds are silvery-white and downy.
Hardy zone 6 to 9

Sorbus yuana ( Yuan Whitebeam )
A dense, attractive, upright, broad crowned medium size tree native to western China. It is rare in the wild and is also one of the rarest Sorbus in cultivation. Some records include: largest on record - 50 feet.
The finely serrated, broad elliptical leaves are up to 5 x 4 inches in size.
The foliage is white felt covered when young turning to glossy deep green above and grayish-white beneath. The foliage persists late in autumn often turning intense orange before falling.
The abundant, 0.5 inch white flowers are borne in huge spectacular flattened clusters up to 8 inches across in late spring.
They are followed by abundant, glossy scarlet-red berries up to 0.65 inches wide that persist into early winter. The larger fruit make it more ornamental than Sorbus alnifolia. Fruit yield is up to 30 pounds per tree
The smooth gray bark develops rugged cracks on older trees.
The branchlets are red-brown when young.
Hardy zone 5 to 8. It thrives in continental climates and is well adapted to the eastern United States.

Others

'Coral Beauty'
Similar to Sorbus aucuparia which it partially descends from.
Some records include: 20 years - ; largest on record -
Has brilliant orange-scarlet berries.
Hardy zone 6 to 9

'Sunshine'
Similar to Sorbus 'Coral Beauty'

'Wilfred Fox'
A very beautiful, massive, sturdy, dense, dome shaped tree resembling the Oak in habit.
Some records include: 25 years - 47 feet; largest on record - 60 x 50 feet with a trunk diameter of 2.6 feet.
The leaves, up to 5 x 3 inches are glossy deep green above and white beneath.
Hardy north to zone 5

10 comments:

  1. Yes, most awesome! But Sorbus Scopulina is far hardier than zone 5, growing in the interior of Alaska (zone 1) in places where precipitation is only about 10 inches.

    ReplyDelete
  2. Your post are really Good. Thanks for great information about Sorbus.

    ReplyDelete
  3. Was just checking out your blogger...alot to look forward to reading. Alot of great photography too!

    ReplyDelete
  4. This comment has been removed by the author.

    ReplyDelete
  5. Is Sorbus 'Decora REALLY fireblight resistant?
    Nobody seems to agree...

    ReplyDelete
  6. Likely S. decora is mostly fire blight resistant north of zone 5. In areas with hot humid summers it is poorly adapted and would grow with little vigor and probably have a greatly increased susceptability to fire blight. Sorbus alnifolia would be the best choice for temperate regions with warm to hot humid summers.

    ReplyDelete
  7. Thank you, I'm in Montréal ( zone 5b) and I can't decide which one would be a better choice for fire blight resistance : Sorbus Decora or Sorbus Aucuparia 'Cardinal Royal' ; Alnifolia would become too large, I fear...

    ReplyDelete