Monday, January 18, 2010

Caragana

A genus of close to 80 species of deciduous shrubs ( also a few trees ) that are part of the larger Legume family.
They prefer climates with hot summers and cold winter, and to be situated in full sun to partial shade on just about any neutral to somewhat alkaline, deep, well drained soil. Most thrive on sandy soil and tolerates poor soil due to their ability to produce their own nitrogen. Caragana's are very drought and salt tolerant as well as tolerant of ice, wind, storms and urban conditions. They are not eaten by deer. Leafhoppers and spider mites may sometimes damage foliage but otherwise insect pest and disease problems are rare.
Old wood doesn't always resprout so vigorously so hard pruning is not really a good idea, however light triming, shaping or limbing up is ok.
Propagation is from seed ( planted outdoors during autumn or soaked 24 hours in hot water before sowing if during spring ). Cultivars may be reproduced from softwood cuttings after blooming is finished or grafting.

Caragana arborescens ( Siberian Pea Shrub )
A rapid growing, erect shrub or small tree reaching around 18 feet, that is native from Siberia; south into Kazakhstan to northwest Mongolia & northwest China. Some records include: fastest recorded growth rate - 4 feet; 5 years - 15 x 9 feet; largest on record - 40 x 33 feet with a trunk diameter of 6 inches. It is an excellent hedge and windbreak on windblown exposed sites. It resprouts vigorously if coppiced.
The pinnate leaves, up to 6 inches in length, are composed of 8 to 14 bristle-tipped, oblong leaflets, up to 1.3 x 0.5 inches in size. The foliage emerges bright green early in spring, turning to deep green during summer, then to yellow in autumn.
The fragrant, bright yellow flowers, up to 0.7 inches long, are borne in clusters of 1 to 4 during late spring into early summer.
They are followed by pods, up to 2.3 inches long, during late summer into early autumn. Each pod contains many seeds.
The young stems are covered in very fine hairs.
Hardy zones 2 to 7 in full sun on sandy, fertile, well drained soil. Siberian Pea Shrub will thrive in climates with as little as 16 inches of precip per year, making it an excellent landscape plant on the Great Plains, the Canadian Prairies and even interior Alaska. Caragana's are very wind, salt and drought tolerant but hate competition from sod and weeds. Propagation is from semi-ripe cuttings or seed soaked 48 hours before sowing.

* photos taken on August 3 2010 @ Univ. of Guelph Arboretum, Ontario


* USDA-NRCS PLANTS Database / Herman, D.E., et al. 1996. North Dakota tree handbook

* excellent photo link found on internet
http://luirig.altervista.org/cpm/albums/bot-units04/caragana-arborescens66168.jpg

'Lorbergii'
Very narrow grasslike leaflets; otherwise similar to species.

'Nana'
A dwarf form reaching a maximum size of 7 x 7 feet with twisted short branches, or up to 10 x 8 feet as a grafted tree. Prune hard every few years for thick, vigorous growth.

'Pendula'
Stiffly weeping in habit, typically grafted upon the straight trunk of Caragana pendula. Suckers and trunk sprouts must be removed or it will revert to regular Caragana arborescens. A grafted tree may reach a canopy width as large as 9 feet in 5 years, though usually much smaller, esp. on trees that are pruned. They rarely gain much height above where they are grafted.
They should be staked for a few years after planting until well established and the trunk thickens.

* photo taken on August 2 2010 in Bayfield, Ontario

* photo taken on Aug 4 2013 in Bayfield, Ontario


'Sericea'
Fine silky hairy foliage.

'Sutherland'
A strongly upright, cut-leaf variety with yellow fall color. Reaches a maximum size of 20 x 5 feet. It makes a great windbreak.

'Warrior'
Like 'Sutherland' but single stemmed and vigorous.

Caragana aurantiaca
A small shrub, reaching a maximum height of 5.5 x 5 ( rarely over 3.3 ) feet in size, that is native to central Asia ( from Xinjiang Province in northwest China; south to Afghanistan to northern Pakistsn ).
The leaves are composed of narrow-oblanceolate leaflets, up to 0.9 x 0.2 inches in size. The foliage is deep green.
The orange-yellow flowers are borne during early summer.
They are followed by pods up to 1.6 x 0.2 inches in size.
The bark is greenish-gray.
Hardy zones 2 to 6.

Caragana borisii
A deciduous, small shrub, reaching up to 4.3 feet in height, that is native to central China.
The pinnate leaves are composed of 8 to 20 elliptical leaflets, up to 0.8 x 0.5 inches in size.
The yellow flowers, up to 1 inch long, are borne in clusters of 1 to 3 during late spring.
The twigs are purplish-brown while the older branches are brown.
Hardy zones 3 to 7.

Caragana brevispina
A large shrub, reaching up to 8 feet in height, that is native to the northwest Himalayas ( from northern Afghanistan to northern Kashmir ). Some records include: largest on record - 15 feet
The pinnate leaves, up to 4 inches in length, are composed of 8 to 14 obovate or oblong leaflets, up to 1 x 0.5 ( rarely over 0.7 ) inches. The foliage is silky beneath. The leaf rachis has prickles beneath.
The soft yellow ( tinted orange-red ) flowers, up to 1 inch in length, are borne in clusters of 2 to 4 during early summer.
They are followed by pods up to 2 inches in length.
The young stems are covered in fine hairs.
Hardy zones 3a to 8

Caragan franchettii ( Franchet Peashrub )
A deciduous shrub, reaching up to 10 feet in height, that is native to southwestern China ( Tibet, northwest Yunnan and western Sichuan ). Some records include: 10 years - 8 feet.
The pinnate leaves are composed of 10 to 12 oblong leaflets, up to 0.4 x 0.1 inches in size. The foliage is gray-green.
The yellow flowers are borne during late spring.
The stems are smooth and gray-green.

* excellent photo link
http://etc.usf.edu/clippix/picture/franchet-peashrub-at-the-arnold-arboretum-of-harvard-university.html

Caragana frutex ( Russian Pea Shrub )
An fast growing, upright, twiggy, spineless, suckering, often thicket forming shrub. It is native from eastern Europe to southern Siberia; south to Kazakhstan to Xinjiang Province of China to southwest Mongolia. Some records include: 10 years - 10 x 8 feet; largest on record - 10+ x 10 feet; longest lived - 20 + years.
The pinnate leaves are composed of 4 oblong or obovate leaflets, up to 1 x 0.2 inches in size. The leaf rachis does carry a few thorns. The deep green foliage is disease free and remains lush all season.
The yellow flowers, up to an inch in length, are either borne single or in clusters of 2 or 3 during late spring.
The stems are deep gray-green; turning to yellowish-gray or brown with age.
Hardy zones 2 to 6. Very tolerant of both drought and salt, making it an excellent choice for use in parking lots. The Russian Pea Shrub thrives even in interior Alaska & Alberta's harsh climate but requires acidic soil. Unlike some other Caraganas, this one can take pruning very well.

* excellent photo link found on internet
http://www.hgtvgardens.com/flowers-and-plants/russian-peashrub-caragana-frutex
http://luirig.altervista.org/cpm/albums/bot-units43/caragana-frutex39471.jpg

'Globosa'
A compact form reaching up to 4 x 3 feet, rarely as much as 6 x 4 feet.
Some records include: 5 years - 2.5 x 3 feet.

'Macrantha'
Larger flowers, up to 1.3 inches.

Caragana jubata ( Shagspine Peashrub )
A somewhat open, medium-sized shrub, reaching up to 10 feet, that is native to northern Russia and western & northern Mongolia; south to Nepal to central China.
The pinnate leaves, up to 2.5 inches in length, are composed of 8 to 12 oblong leaflets, up to 0.7 x 0.2 inches in size. The leaflets are borne on a spiny somewhat woolly rachis that persists on the branch after the leaves drop in autumn.
The white to pale purple flowers, up to 1.5 inches long are borne singly during early summer.
They are followed by a pod, up to 1.2 inches in length, during late summer into early autumn.
The stems are dark gray to dark brown.
Hardy zones 2 to 7 preferring extremely hot summers and very cold winters. It thrives on the northern Great Plains but is very tempermental in wetter climates further east including Ontario.

Caragana korshinskii
A deciduous, large shrub, reaching a maximum height of 13 feet, that is native to southeast & eastern Mongolia; south to northwest through north-central China.
The pinnate leaves are composed of 12 to 16 oblanceolate leaflets, up to 0.3 x 0.2 inches in size.
The yellow flowers, up to 0.9 inches in length, are borne singly during late spring into early summer.
They are followed by pods up to 1 x 0.3 inches in size, during mid-summer.
The stem are glossy golden-yellow.
Hardy zones 2 to 6.

Caragana leucophloea
A rounded, deciduous shrub, reaching up to 5 feet, that is native from Kazakhstan to most of Mongolia; south to northwestern & north-central China.
The pinnate leaves are 4 foliate. They are composed of narrow-oblanceolate leaflets, up to 0.5 x 0.1 inches in size. The foliage is mid-green above, pale green beneath.
The bright yellow flowers, up to 0.7 inches in length, are borne singly or in pairs during late spring into early summer.
They are followed by pods up to 1.5 inches in length, during mid to late summer.
The twigs are purplish-red. The older stems become pale yellow, eventually changing to black on very old stems.
Hardy zones 2 to 6.

Caragana maximowiczii ( Maximowicz Peashrub )
A dense, spreading, medium-size shrub, that is native to southern Russia and Tibet. Records include: 10 years - 6.6 x 10 feet; largest on record - 6.6 x 15 feet. It is very rare and little known outside its natural range.
The pinnate leaves are composed of 4 obovate leaflets. The foliage is bright green to blue-green.
The bronze-yellow flowers are borne during early summer.
The spines are up to 2 inches long.
Hard zones 2 to 8

Caragana microphylla ( Littleleaf Caragana )
A medium-size, deciduous shrub, reaching up to 10 x 10 feet, that is native to rocky slopes and sand dunes from southern Siberia; south to north & eastern Mongolia to northeast China. It is similar to Caragana arborescens but much lower and more spreading in habit. Some records include: fastest recorded growth rate - 1.5 feet; 10 years - 10 x 10 feet; largest on record - 11 x 16 feet. It is valuable in dry continental climates for preventing desertification.
The pinnate leaves, up to 3 inches in length, are composed of 12 to 20 oblong or obovate leaflets, up to 0.5 x 0.3 inches in size. The foliage is dull green.
The yellow flowers, up to 1 inch in length, are borne either singly or in pairs during late spring into early summer.
They are followed by pods up to 2 x 0.2 inches in size, during mid to late summer.
The dull gray-green stems are armed with spines at the base of the leaf.
Hardy zones 2 to 7, thriving even in southeast Alaska.

Caragana pekinensis ( Peking Peashrub )
A shrub, reaching up to 6.5 feet in height, that is native to central China.
The pinnate leaves are composed of 12 to 16 elliptical leaflets, up to 0.5 x 0.3 inches in size.
The yellow flowers, up to 1 inch in length, are borne either singly or paired during late spring.
They are followed by pods up to 2.4 inches in length.
The bark is brown.
Hardy zones 2 to 6.

Caragana pygmaea ( Pygmy Peashrub )
An attractive, fast growing, dense, domed, small, deciduous shrub to 3 x 6 feet, that is native to rocky slopes and sand dunes from eastern Russia; south thru most of Mongolia to northeast China. Records include: fastest recorded growth rate - 1 foot; 10 years - 8 x 6.5 feet; 14 years - 8 x 11.5 feet; longest lived - 40 + years. Can be used as a low hedge.
The leaves are usually composed of 4 linear to oblanceolate leaflets, up to 1.2 x 0.1 inches in size. The foliage is blue-green.
The hanging, bright yellow flowers, up to 1 inches in length, are borne during late spring.
The bark is glossy golden-yellow.
Hardy zones 2 to 6, it is very tolerant of harsh climates and even thrives on the Canadian Prairies and in southeast Alaska. Pygmy Peashrub is tolerant of drought and alkaline soils. Propagation is from semi-ripe cuttings.

subsp. altaica
Also called Caragana altaica. A small, deciduous shrub, reaching up to 3.3 feet. It is native to western Mongolia and far northwestern China.
It i similar to the species but the flowers are larger, up to 0.8 inches long.
Hardy zones 2 to 6.

Caragana robrovskyi ( Robrovskyi Peashrub )
A large shrub, reaching up to 10 x 7 feet in 5 years though often much less on harsh sites.
The pinnate leaves are composed of 6 to 12 oblong or obovate leaflets, up to 0.4 x 0.2 inches in size. The foliage is bright green.
The yellow flowers, up to 1.1 inches in length, are singly borne during late spring.
They are followed by pods, up to 1.2 inches in length, during mid-summer.
The bark is yellowish-brown.
Hardy 3 to 6.

Caragana rosea ( Pink Peashrub )
A tough, spined, upright arching shrub, reaching up to 4 feet, that is native from central to northeast China.
The leaves are composed of 4 obovate leaflets, up to 1 x 0.5 inches in size.
The rose-pink ( eventually deepening to reddish ) flowers, up to 1 inch in length, are borne during early summer.
They are followed by seed pods, up to 2.4 inches in length.
The bark is greenish-brown.
Hardy north to zone 3 preferring dry alkaline soil.

Caragana sinica ( Chinese Peashrub )
A rapid growing sparse shrub, reaching a maximum size of 8 x 6 feet, that is native a widespread native of China and Korea.
The pinnate leaves are composed of 4 obovate leaflets, up to 1.4 x 0.6 inches in size. The glossy green foliage turns to yellowish-green during autumn.
The creamy to light yellow ( flushed with red ) flowers, up to 1.2 inches, are borne singly during late spring.
The bark is dark brown. The branches are angled.
Hardy zones 3 to 8 ( possibly 2 for Liaoning seed source ) in full sun on well drained to sandy soil. Requires climates with hot summers and cold winters.

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


* photos taken on Apr 17 2016 @ U.S. National Arboretum, DC


Caragana spinosa
A rounded, small to medium-sized, deciduous shrub, reaching a maximum size of 8 x 10 ( often under 2 ) feet in size. It is native from Siberia; south to Kazakhstan to northwest China thru most of northern Mongolia.
The pinnate leaves are composed of up to 6 narrow leaflets, up to 1.2 x 0.2 inches in size. The foliage is mid-green.
The showy, intense bright yellow flowers, up to 0.8 inches long, are borne during early summer.
They are followed by pods up to 1 x 0.2 inches in size.
The spiny twigs are reddish-brown. The older stems are yellowish-brown.
Hardy 2 to 6.

Caragana stenophylla ( Threadleaf Caragana )
A deciduous, small shrub, reaching up to 2.6 feet, that is native to eastern Russia, Mongolia & much of northern China.
The pinnate leaves are typically composed of 4 linear leaflets, up to 0.5 x 0.1 inches in size. The foliage is gray-green to mid-green.
The bright yellow flowers, up to 0.8 inches in length, are borne singly during late spring.
They are followed by pods up to 1 inch in length, during late summer.
The bark is gray-green to yellowish-brown. The bark may become deep brown on very old plants.
Hardy zones 2 to 6.

Caragana tibetica ( Tibetan Caragana )
A deciduous, domed, small shrub, reaching up to 1 foot in height, that is native to southeast Mongolia; south to Tibet to central China.
The pinnate leaves are composed of 6 to 8 linear leaflets, up to 0.5 x 0.1 inches in size.
The bright yellow flowers, up to 1 inch in length, are borne singly during late spring.
They are followed by a small pod up to 0.4 inches in length.
The stems are downy bright gray-brown at first, later turning to grayish-yellow.
Hardy zones 4 to 7.

Caragana tragacanthoides ( Spiny Red Caragana )
A spiny shrub, reaching up to 5 x 5 feet, that is native to central Russia, Kazakhstan, Mongolia & Xinjiang Province in northwest China. A subspecies is native to high mountains of Kashmir. Some records include: 2 years - 3.5 feet; 4 years - 4 x 3 feet. The stems are reddish.
The leaves are composed of 4 to 6 narrow-oblanceolate leaflets, up to 0.5 x 0.1 inches in size.
The bright yellow flowers, up to 0.8 inches in length, are borne during early summer.
Hardy zones 3 to 8, in sun to partial shade; it is especially well adapted to central North America and the Rockies. Hardy in milder parts of Alberta.

* excellent photo link below
http://www.hkolster.nl/home-nl/+fotobestanden/+caraganatragacanthoides.htm

Caragana turkestanica ( Turkestan Pea Shrub )
A deciduous, large shrub, reaching up to 6.5 feet, that is native to Kyrgyzstan and northwestern China. Some records include: largest on record - 18 feet.
The pinnate leaves are composed of 6 to 10 elliptic or obovate leaflets, up to 0.8 x 0.3 inches in size.
The yellow flowers, up to 1.1 inches long, are borne singly during late spring.
They are followed by a pod up to 2 inches in length, during mid-summer.
The stems are gray-green, later turning to gray.
Hardy zones 2 to 7, it thrives even on pure sand. Shelter from excessive wind for the first 3 years. It is less mildew prone than the closely related similar Siberian Pea Shrub. Kyrgyzstan

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