The radish is an annual and chiefly bees pollinate the flowers. The distance between different sorts, including the black radish, must be at least 500 m to get pure seeds of each sort. Up to 1000 m could be necessary to guarantee absolute pure seeds.

Despite the radish blooming quickly and setting seeds, they need a long time to ripen completely. Sow as early as possible in a hotbed or greenhouse and as soon as the radishes are just over half-grown, pull them out and sort through. Eat all the miss-shaped ones and the badly coloured ones. With the rest, cut off the tops, leaving 3 cm (do not harm the small leaves inside the leafage), set out outdoors with 20-30 cm of mutual distance with the growth-point exactly at the surface. Water afterwards! Even sowing very early in a plot could succeed if the summer and the autumn are long. Thin out to correct mutual distance but you cannot look through them to improve the sort.

The first blooming ones among both the planted ones and the sown ones should be removed as they have no good genes to propagate.

During summer the almost metre-tall stems flower with white, pink and violet flowers turning into thick pods of 3-9 seeds. They do not fall off as they do in other common species of the cabbage family.  The whole plant is harvested when the pods have turned light brown, almost white. They need to continue drying indoors before threshing. The pods are hard and therefore, larger amounts are threshed with a flail or threshing mill. Smaller amounts are crushed by hand. Remove the rubbish by sieving and winnowing or allow the seeds to roll away from the rubbish on a sloping surface.