Plant · P-240

Adzuki Bean

Vigna angularis (Willd.) Ohwi & H.Ohashi

Adzuki is the odd one out among the beans in this group: a very hot summer is actively too hot for it, since heat above about 35C damages pollen viability in a plant that pollinates itself, costing pod set directly. The fix is timing rather than avoidance - sown in August so flowering lands after the worst heat breaks, it still matures well ahead of the first frost. The mature seed is the bean behind sweet red-bean paste in East Asian confectionery, a genuinely different product from every other bean here, and it also sprouts, cooks as a vegetable in the young pod, and roasts as a coffee substitute. Its roots fix nitrogen and are best left in the ground at harvest so the crop after it gets the benefit.