A tub will produce sprigs each day and the greens can be used in sandwiches and salads. There are two basic varieties, watercress and wild watercress. Watercress seeds should be germinated at about 100 seeds per tub, and then thinned by harvesting as the plants grow. The taller stems should be harvested first and the plant should recover each day. Also, when the leaves get too tight on top the plant can start to rot within.
Harvest leaves in such a way that remaining leaves have some space from other leaves.
Watercress leaves can be used in salads and sandwiches. If you have extra they can also be added to soups and stews. They can also be boiled and served as a vegetable, but this loses some of their food value. They should be picked fresh and eaten within one half hour from being picked to retain full food value. Cultivated Watercress - Spinacia spinosa is a bushy plant made up of dark green ruffled and pointed leaves.