Siberian peatree
Caragana boisii

Family: Fabaceae or Leguminosae

What it is like

Caragana boisii is a deciduous Shrub growing to 2 m (6ft) by 1.5 m (5ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 2. It is in flower in May, and the seeds ripen in September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers dry or moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Height (m): 2

Where it is found

Not known

E. Asia - China.

Conservation Status:

Countries/locations it is found in

Asia, China,

How it is used

Food

Rating: 4

The following uses are for the closely related C. arborescens and can probably also be applied to this species. 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. Young pods - cooked and used as a vegetable.

Oil: Oil

Seed: includes nuts, cereals, peas and beans.

Seedpod: things such as Okra, French and Runner beans.

Medicine

Rating: 0

Other

Rating: 4

The following uses are for the closely related C. arborescens and can probably also be applied to this species. A fibre is obtained from the bark, used for cordage. A blue dye is obtained from the leaves. The seed contains 12.4% of a fatty oil. 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.

Dye: Plants that provide dyes.

Fibre: Used for making cloth, rope, paper etc.

Hedge: Plants that can be grown as hedges.

Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.

Shelterbelt: Wind resistant plants than can be grown to provide shelter in the garden etc.

Soil stabilization: Plants that can be grown in places such as sand dunes in order to prevent erosion by wind, water or other agents.

Attracts Wildlife: Plants noted for attracting wildlife

Hedge: Hedge

Nitrogen Fixer: Plants that fix nitrogen in the soil

How it is grown

Succeeds in most well-drained soils, preferring full sun and a light sandy dry or well-drained soil. Tolerates very alkaline soils. Does not require a rich soil, succeeding on marginal land. Established plants are drought resistant. Fast growing. This species is hardy to at least -30°c, it prefers a continental climate with hot summers and cold winters so it does not grow so well in the milder western half of Britain. This species is closely related to C. arborescens, differing in the longer teeth of the calyx and in the downy ovary and young fruit. It can probably be used in all the ways C. arborescens is used and therefore has an excellent potential for human food.. 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.

Propagating it: 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. Cuttings of half-ripe wood, 7 - 10cm with a heel, July/August in a frame. Layering in spring.

Best place to grow: Woodland Garden Sunny Edge; Hedge;

Habit: Shrub

Hardiness: 2-9

Growth: Fast

Soil: Light (sandy), medium

Shade: No shade

Moisture: Dry, moist

Things to keep in mind

The following report belongs to the closely related C. arborescens. Reports that this plant contains toxins have not been substantiated. The occurrence of cystine in the seeds is doubtful.

Its other names

Local names

Synonyms

C. microphylla crasse-aculeata. C. arborescens crasse-aculeata.