Watercress ( Nasturtium officinale) is a member of the brassica family, which also includes broccoli, cabbage and cauliflower. All contain natural phytochemicals, which have anti-cancer properties. However, watercress has other nutritional benefits: it’s rich in many vitamins, including A, B1, B2, B9 (folic acid), C, D, E and K as well as minerals, including calcium, iodine, iron, manganese, phosphorus and zinc. The mustard oil present in watercress also has antibiotic and anti-inflammatory properties. A two-year study by the University of Ulster concluded that eating watercress daily has the ability to resist DNA damage caused by free radicals. Watercress can be used as a salad green, steamed like a vegetable, or added to soups, sandwiches and omelettes to add a peppery bite.
In the right conditions, watercress can survive in the garden almost indefinitely. It does best in wet but well-drained soil, such as stream edges, but it can be grown in tubs flooded periodically with water. Old concrete sinks work particularly well. Start from seed or cuttings. Watercress appreciates plenty of lime.