Caragana korshinskii Seeds | Korshinsk Peashrub
LATIN NAME: Caragana korshinskii
COMMON NAME: Korshinsk Peashrub
Plant Profile
Korshinsk peashrub is a leguminous shrub of two to three metres with grey-green compound leaves, yellow pea flowers in May and a dense thicket of upright stems. It grows on the dry steppe and in the sandy deserts of Ningxia, Gansu and Inner Mongolia, where rainfall may be under two hundred millimetres.
It is the plant behind the shelterbelts of northern China, planted by the million along roads and around fields, and it is cut every few years for fuel and for fodder. The local name, ning tiao, is on the signage of every sand-control project in the region. A mature stand is cut on a rotation rather than clear-felled, and the stumps resprout within a month.
Science & Biotechnology
The shrub survives drought by reaching for water rather than by conserving it: the taproot can go five metres down and the lateral roots spread twice the height of the plant, which is how it finds moisture in sand that is dry at the surface. That same root system binds a dune in place within three seasons.
The seed coat is hard enough that a third of a batch may still be impermeable after a year in storage, and direct sowing gives an uneven stand. Mechanical scarification or a short soak in hot water raises germination to eighty per cent, and inoculation with the right rhizobium is needed on ground that has never grown the species.
Uses & Benefits
The shrub is cut on a five to six year rotation for fuelwood, and the regrowth is fast enough that a stand can be worked indefinitely. The leafy branches are fed to sheep in winter, when nothing else is available, though the spines make handling unpleasant and the feed is coarse.
The seed is rich in protein and is ground into a meal for livestock in some districts, and the flowers are a minor honey source in the steppe. The plant is also used as a nurse crop for trees on reclaimed mine land, since it fixes nitrogen and shelters seedlings from wind.
Growing from Seed
Scarify the seed, soak it for twelve hours in warm water and sow in spring at two centimetres, in rows fifty centimetres apart. Germination takes a week to ten days in warm soil, and the seedlings are fast enough to be planted out in the first autumn.
The shrub needs full sun and free drainage, and it will not tolerate a wet site or heavy clay. Cut it back to ten centimetres every fifth year to keep the stand productive and to stop it becoming leggy. It suckers from the roots after cutting, which is a virtue in a shelterbelt and a nuisance in a border.
Our Take
A drought-proof shrub for sand, wind and bad ground, and one of the few legumes that will grow where the rainfall is under two hundred millimetres. Not a garden plant.
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