An excellent source of vitamin K and a good source of calcium, watercress helps maintain strong bones and healthy blood clotting. It also donates about half the RDA of both antioxidant vitamins A (also in the form of beta carotene) and C. These are key factors in protecting cells and organs from oxidative damage by free radicals. They also help support a healthy immune response, eyesight, skin and cardiovascular system (by preventing plaque build up and maintaining elasticity in blood vessel walls). Watercress also has small amounts of vitamins B1, B6, E and the minerals magnesium, iron, iodine and zinc. These support the thyroid gland, stimulate metabolism, synthesize red blood cells and stimulate the production of antibodies to fight infections. Watercress has the phytonutrients lutein and zeaxanthin, which work alongside beta-carotene and vitamin A to maintain healthy eyesight. The glucosinolates help boost and regulate the liver’s production of detoxification enzymes. The phenylethyl isothiocyanates in watercress are being studied for their potential to fight the development of cancer cells.
Vitamin and Mineral Content
Vitamins – K, C and A
Minerals – Calcium, Manganese and Potassium
Regularly eating watercress may help reduce the risk of cardiovascular disease, heart attack, stroke, cataracts, gout, osteoporosis, lung cancer, breast cancer and potentially many other cancers.
How to Grow
Watercress is a great addition to soups, salads, sandwiches, dips and sauces. It grows naturally in running rivers and streams, but is also easy to cultivate in the backyard. It prefers to grow in shade with excellent water retention. Dig a trench about 1 foot deep. Layer the bottom with some aged compost/manure or planting mix. Work in some organic matter with the soil dug out and fill the trench. In early spring, sow seeds at temperature close to 55˚F. If sowing indoors, use seed trays. When the seedlings get big enough, transfer them to another tray with wider spacing using a mini dibber and holding onto the leaves only. Do not touch the stems during the transfer. Plant them out in late spring to early summer spacing them out by about 4 inches. If your climate is warm enough, sow seeds outside in shallow drills. Once they grow a bit, remove the weaker ones and leave a spacing of about 4 inches. Another way is to buy a bundle of watercress, take the shoots with a couple young roots showing and plant them in the same spacing. Water generously and often. Keep the bed weed free by handpicking and/or hoeing. No other fertilizing is needed. Pinch the dominant shoots and remove any flowers as soon as you see them. Harvest the shoots as needed. They come back for another harvest until temperatures drop in fall.
Watercress is largely pest free. If something you do not recognize begins to infest, take one of the pests to the nearest nursery and/or agricultural extension office for an ID and advice on the best treatment.
Watercress can be grown indoors in pots with drainage holes. Place pots on an open tray of water. Refill the tray as soil soaks up water. Keep the soil damp. Prevent flowering by pruning buds immediately. Greens wither and wilt quickly. Use right after harvesting.