Radishes

Mother Earth News, Sep/Oct 1987
The Easiest Seed-Saving Crops
By Nancy Bubel

Most radishes are another exception because spring sown plants will produce seed pods by summer. Let the pods dry on the plant, but pick them before they split and scatter the seed. Such biennial radishes as Japanese daikon and China rose should be over wintered in a root cellar and replanted 12 inches apart in spring. They'll produce seed by early summer.

The Arc Institute

Mature quickly and can be planted between rows of carrots or parsley to keep the soil moist. Not high in nutrients. Plant seeds 1” apart in rows 18” apart, in soil that is cool and moist rather than hot and dry.