Adzuki Bean

Sowing: Adzuki bean is direct-sown in spring once the soil has warmed to around 65°F, with seed set about half an inch to an inch deep and watered frequently until germination; seedlings are thinned to roughly three inches apart, and mulching plus early weeding help the plants establish, since growth is notably slow at first even in warm weather.

Growing: The plant develops a taproot reaching 40 to 50 centimetres deep, needs no staking, and tolerates cool conditions well enough to suit shorter or maritime growing seasons; it also copes with poor soils and moderate drought but cannot survive frost. Flowering continues for 30 to 40 days, the crop is mainly self-pollinating though cross-pollination occurs, and plants typically reach maturity between 80 and 120 days depending on conditions.

Adzuki bean is susceptible to a number of pests and diseases, including white mold and curly top virus.

Picking: Pods can be picked young and green for fresh eating, or left on the plant until they mature and dry for shelling; because pods shatter as the seeds ripen, harvesting at the right moment can be difficult.

Drying and storage: For dried beans, the whole plant is cut at season's end and hung indoors to dry before the pods are shelled, or collected and winnowed once dry; the beans are dried completely before being stored in a sealed container in a cool, dry place.

Culinary: Adzuki bean is grown chiefly for its edible seeds, used across East Asian cuisine in both sweet and savoury dishes, including sweetened bean paste for pastries and confections and a hot, tea-like drink, and it is often paired with rice. Young green pods can be eaten fresh like snow peas, and mature seeds are commonly sprouted.

Traditional: Within Western macrobiotic dietary traditions, adzuki beans have been used in the belief that they support kidney and adrenal function.

The wild ancestor of the cultivated adzuki bean is thought to be Vigna angularis var. nipponensis, a form distributed across East Asia, with wild adzuki likely originating near the Himalayas before spreading naturally into central China. Speciation between the wild and cultivated varieties is estimated to have occurred around 50,000 years ago, and the crop may have been independently domesticated in Korea, Japan, and China, where it has since been cultivated for thousands of years.