Salix koriyanagi aka Kori Yanagi Willow

Salix koriyanagi is a deciduous shrub in the willow family, Salicaceae. Its common names include kori-yanagi and Japanese basket osier. Kew lists Korea as its native range. Other sources extend its range to eastern China or Japan. It grows in temperate climates and loses its leaves each year. It is not native to Britain or Ireland.

This upright, bushy willow has thin, flexible, reddish-purple stems. The RHS gives a garden height of 8–13 feet [2.5–4 metres]. Its shorter account describes plants reaching about 10 feet [3 metres]. The spread is about 3–5 feet [1–1.5 metres]. Plants take around 10–20 years to reach their full size. The narrow leaves reach about 0.33 feet [0.1 metres] long. New leaves show orange and red tones in spring. They later turn bright dark green above and blue-green beneath. Slender catkins appear in spring. Male catkins bear orange anthers.

Grow this willow in full sun with moist or wet soil. It accepts clay, loam, sand, and chalk soils. Acid, neutral, and alkaline conditions all suit it. The RHS lists both moist, well-drained soil and poorly drained sites. It also accepts exposed or sheltered positions. The RHS rates its hardiness H5, while PFAF lists USDA zones 5–9. Softwood cuttings can be taken in early summer. Hardwood cuttings provide another way to raise plants in winter.

This shrub suits informal gardens, wildlife plantings, hedges, and screens. Its spring leaf colour and coloured stems offer garden interest. Basket makers use its tough, flexible red or russet stems. Plants grown for weaving are usually coppiced each year. A two-year cycle gives thicker poles for basket uprights. PFAF lists no known edible uses and gives edibility zero. It reports no known hazards, but this does not establish safety. PFAF also gives it a medicinal-use rating of two out of five.

Several pests may attack this willow. These include aphids, caterpillars, leaf beetles, sawflies, and willow scale. Possible diseases include willow anthracnose, scab, canker, rust, and honey fungus. These are listed risks, not problems every plant will face. PFAF does not flag the species as a weed risk.