Hemerocallis thunbergii

Hemerocallis thunbergii is a deciduous perennial in the Asphodelaceae family. Gardeners also call it the late yellow daylily. Kew places its native range in eastern and southern Hokkaido, Japan. Other sources give different ranges in East Asia. RHS lists China and Korea; PFAF mentions South Korea and Japanese mountains. It grows in a temperate climate and forms leafy clumps.

Arching green leaves give each clump a soft outline. The leaves are long and shaped like straps. Plants reach about 4 feet [1.2 metres] when flowering. RHS gives a garden height of 3.3–4.9 feet [1–1.5 metres]. Clumps spread 1.6–3.3 feet [0.5–1 metre] across. Narrow, lemon-yellow flowers appear in summer above the foliage. The leaves die back as the growing season ends. Plants take two to five years to reach full size.

Choose full sun for the best flower display. Plants also grow in partial shade, but deeper shade reduces bloom. Fertile soil that stays moist yet drains well suits them best. They tolerate heavy clay and soil with fewer nutrients. Chalk, loam and sand also suit this species. It accepts acid, neutral and alkaline soil. Water during dry spells from spring into early summer to support flowering. RHS rates it H6, while PFAF lists USDA zones 4–8.

Use it in flower beds, borders and informal cottage gardens. RHS also suggests it for coastal gardens. PFAF lists meadow planting and sunny woodland edges among its uses. Divide clumps in early spring or early autumn. Remove spent flower stems and clear away dead leaves. Aphids, slugs, snails, thrips and spider mites may attack it. Daylily gall midge can also cause trouble. Possible diseases include fungal leaf spot, rust, and bacterial leaf or stem rot.

PFAF reports food uses for young leaves, shoots, flowers and buds. It describes cooking very young leaves and shoots before they grow fibrous. Flowers and buds have raw or cooked uses. Dried flowers can help thicken soups. These reports do not establish that eating the plant is safe. PFAF warns that large amounts of leaves may cause hallucinations. Its account of blanching as a safeguard is unclear. RHS warns that the plant is toxic to cats. PFAF also records traditional root remedies, not evidence of proven treatments. Tough dried leaves have been woven into cord and footwear.