Common Name: Siberian Pea Tree

General Information

Caragana arborescens is a much-branched deciduous shrub or a small tree ; it usually grows 2 - 5 metres tall, occasionally reaching 7 metres. Rarely, it is a rather low shrub[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is cultivated on a small scale as a medicinal plant in Korea; can be used in soil stabilization and woodland regeneration programmes; is widely grown as an ornamental in gardens; and can be used as a hedge and shelterbelt[, ].

Known Hazards

Reports that this plant contains toxins have not been substantiated[]. The occurrence of cystine in the seeds is doubtful[].

Botanical References

, ,

Range

Asia - Kyrgyzstan, Kazakhstan, western Siberia, eastern Siberia, Mongolia, northern China

Habitat

River banks, pebbles, sands, open forests and forest edges, gully slopes and stony slopes in the forest belt; rarely occurring on the periphery of the steppe belt and there, for preference, in shady habitats[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	3.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Wild

Cultivation Details

Caragana arborescens is a very cold-tolerant species - dormant plants are hardy to about -30°c[]. However, it prefers a continental climate with hot summers to ripen its wood, and does not grow so well in areas with mild, especially wet winters - in such a situation the plant can be stimulated into growth too early in the spring, this young growth being susceptible to frost damage[].
Succeeds in most well-drained soils, preferring a position in full sun and a light sandy dry or well-drained soil[, , ]. Tolerates very alkaline soils[]. Plants do not require a rich soil[, , ], succeeding on marginal land[]. Established plants are drought resistant[].
A fast growing plant[]. Plants take 3 - 5 years to reach commercial bearing size, good crops are then usually prroduced every year[].
The Siberian pea shrub has an excellent potential to become a staple food crop. The seed is nutritious and wholesome, although rather small it is often very freely borne and is easily harvested[]. This species has also been recommended as a nitrogen-fixing windbreak and ground cover plant that binds the soil and produces fibre and dye stuffs[].
Caragana boisii and Caragana fruticosa are closely related to this species[] and can probably be used similarly[].
A very ornamental plant, some named forms have been developed for their ornamental value[]. 'Nana' is a very compact dwarf form[] that grows slowly[]. 'Pendula' has stiffly pendent branches but is otherwise the same as the type species[].
A good bee plant[].
Plants in this genus are notably resistant to honey fungus[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

Seed - cooked[, ]. Small but produced in abundance[], there are 4 - 6 seeds per pod[]. A bland flavour, it is best used in spicy dishes[]. The raw seed has a mild pea-like flavour, though we are not sure if it should be eaten in quantity when raw[]. The seed contains 12.4% of a fatty oil and up to 36% protein[, ], it has been recommended as an emergency food for humans[]. More than just an emergency food, this species has the potential to become a staple crop in areas with continental climates[].

Young pods - cooked and used as a vegetable[, , , , , ].

Medicinal

The whole plant, known as ning tiao, is used in the treatment of cancer of the breast, and the orifice to the womb, and for dysmenorrhoea and other gynaecological problems[].

The root is used in the treatment of arthritis, neuralgia, diarrhoea and bone weakness[].

Agroforestry Uses:

The plant can be grown as a hedge[]. It is quite wind-resistant and can also be planted in a shelterbelt[].
The plant has an extensive root system and can be used for erosion control, especially on marginal land[]. Because of its nitrogen-fixing capacity, it is valued as a soil-improving plant[].
The plant is used as a pioneer species for re-establishing native woodland and also for establishing woodland gardens[, ].

Other Uses

A fibre obtained from the bark is used for making cordage[, , , ].

A blue dye is obtained from the leaves[, ].

The seed contains 12.4% of a fatty oil[].

Propagation

Seed - best sown as soon as it is ripe in a cold frame[]. It usually germinates in 2 weeks[]. Stored seed should be pre-soaked for 24 hours in warm water then sown in a cold frame[, , ]. If the seed has not swollen then scarify it and re-soak for another 12 hours before sowing[]. Germination usually takes place within 2 - 3 weeks at 20°c[]. Good percentage[]. As soon as they are large enough to handle, prick the seedlings out into individual pots and grow them on in a greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. There are approximately 40,000 seeds per kilo[].
Cuttings of half-ripe wood, 7 - 10cm with a heel, mid summer in a frame[].
Layering in spring.