Flower panicles and leaves rise from the nodes, both on the main stem and branches. Growth habit is indeterminate with flowers opening throughout a long season, so the seed crop does not mature at one time. The seed is partially but not entirely enclosed by adhering flower parts during development. Buckwheat is usually seeded only after the ground is thoroughly warm in early summer. Plants will begin blooming in about 40 days from seeding and first seeds mature about 35 days later.
Harvesting is done when a substantial part of the seed is ripe.
Fields are then mowed and plants are stacked to dry before they can be threshed. Seeds are pointed, broad at the base, and triangular to nearly round in cross section. They vary in size in different kinds from about 4 mm at maximum width and 6 mm. The seed consists of an outer layer or hull, an inner layer, the seed coat proper, and within this a starchy endosperm and the germ. In milling the hull, which comprises 18 to 20 percent of the whole grain weight, is first removed.