Due to different varieties and cultivation methods, watercress can be divided into two seed saving methods.

(1) Seedlings and seeds. The old stems of watercress are highly resistant to stress and can survive the adverse environment in midsummer. The old stems can be used as seedlings to keep seeds on site, or transplanted to keep seeds, that is, asexual propagation. If cultivated in the open field, the old stems need to be transplanted to a place with shade and rain protection in summer, and in late autumn, the old stems need to be transplanted to a protected area with heat preservation and cold protection to cultivate seedlings.

(2) Seed saving. The tender stems left for planting cannot be harvested and should be allowed to grow fully. They will begin to bloom in June and can be harvested from July to August when the seed pods begin to turn yellow. If harvested not in time, the seed pods will dry and crack and the seeds will scatter. Therefore, harvest the seed pods one after another when they turn yellow, dry the pods in the sun, and store the seeds for later use. Approximately 2 kilograms of seeds can be harvested from every 667 m2 seed field.