Watercress is a succulent, leafy plant that thrives in marshes, bogs and water gardens. The lobed leaves can be eaten raw, cooked or dried. They have a pungent flavor and are crisp. Watercress needs to be harvested before the buds appear as the leaves turn bitter after flowering. It is a fast-growing plant that prefers partial shade. It produces white flowers in mid-summer which are very attractive to bees. Watercress plants are highly ornamental.
Most gardeners will not try growing Watercress because they think that you need running water to be successful, but that is not true.
Watercress does need moisture to grow well, but it can be successfully grown in moist windowsill troughs indoors and larger pots outside, the importance is to keep the compost thoroughly wet. For a more permanent bed you might consider lining and area with polythene before filling up with compost - thus creating a bog area.
Sow 3-4 seeds in pots of moist soil or compost.
Grow on in moist conditions - soggy wet containers, a polythene lined trench with mud and water or even in the pond.
Pick regularly to to prevent premature flowering.
Starting inside: Start seeds in normal seed starting mix. Place the containers in a tray of water and keep the water constantly supplied. Fluorescent lamps or growing lights are needed. The herb seeds can be started indoors 6 weeks before the last expected frost and then transplanted outdoors. The ideal setting is along a pond or stream bank.