Black soybean

black soybean harvested while green

I bought a pack of black soybean seed while traveling in Japan during spring, and the normal green one (Edamame). The green variety did not grow well, the plants stayed small and only produced a very small quantity of beans, unlike what I used to harvest from seeds purchased from UK source.

black soybean plants

The plants of this black variety grows big and healthy, but only started flowering in September, and pods started to fill up to the size that could be harvested now.

Obviously there must be descriptions on the seed packets about growing conditions for these seeds in Japanese that I did not understand!