Watercress is now available all year round, so why do I associate it with Spring? We should remember that watercress used to be harvested as a wild plant and as such would have been one of the first wild greens of the year. It does not grow much in the extreme cold of winter, but as soon as the days grow warmer the acclimatised plant will burst into action, so March until November is its natural season. To secure year-round supplies several British growers have purchased land abroad – in Spain for example, but also as far away as the USA.
The first attempts at commercial cultivation are reported to have been in Germany in the 16th century, whilst the first British watercress farm was opened in 1808 at Springhead in Northfleet, Kent. The key to growing quality watercress is in the quality of the water in which it is grown. As the name of that first farm, Springhead, indicates the water must me pure and springs, particularly arising from chalk land, ensured this purity. However even clear looking streams can be host to the parasite Liver Fluke, which predominantly arrives via sheep but also cattle and even snails. So whilst cultivation might initially have been intended to supplement the wild supply today we know better than to pick it from untested sources, although cooking will kill Liver Fluke.
The development of the railways in Victorian times allowed tons of watercress to be transported up to Covent Garden from the main growing area of Hampshire. The industry continued to thrive during the two World Wars when we were dependent on home grown produce and the high nutritional content of watercress was greatly valued. During the wars watercress sandwiches became an absolute staple. In the 1940s more than 1000 acres of watercress were under cultivation but following the closure of many branch railways and a growing interest in a wider range of salad leaves, watercress beds now cover only about 150 acres of the UK.
How do you choose the best watercress? The water purity issue now taken care of (the NFU has a code of practice guaranteeing this) unless you are lucky enough to live in the growing areas, where I am sure you might taste a difference between waters, freshness becomes my top priority. When sold in Covent Garden, watercress used to be held in cones, in bunches, and eaten in the street rather as one might eat ice-cream. Bunched watercress is still the best way to buy even if you later discard some of the stem, so ignore the bags of cut leaves. My favourite grower, John Hurd, was the first to be certified organic although it has to be said that fertiliser additions are minimal in all production and no pesticides are used because of the water purity issues. Bunches of John Hurd watercress, sold at my local farmers market, simply look the freshest with good sized, dark green leaves. His watercress is also sold in Waitrose, bunched but bagged, and so presumably with the usual gas additions you find in any bagged salads. Watercress remains a regional speciality, being grown only in the chalk stream areas of the south and even via this supermarket distribution, is still primarily available in the south. The key differentiation between small traditional production and the largest producers is mechanisation. Large producers use machines to harvest; propagate seed in greenhouses, at which point fungicides may be used; and restock beds several times a year. Those cutting bunches by hand can be more selective about what they cut, taking only the mature leaves that will have developed the mustard oils that give watercress its distinctive peppery flavour, leaving the smaller leaves to continue growing.
How to use
The wartime habit of using watercress in sandwiches remains one of its most effective uses, although now we can add other ingredients to the sandwich. A sandwich of rare roast beef and horseradish, very fine on its own, is sublime with the addition of watercress and I must admit to being partial to the French sandwich variation of Brie in a Baguette when it is accompanied by watercress.
A natural partner in its original habitat of chalk land streams would be trout, although finding a worthy trout today is somewhat harder than of old. Watercress is however a perfect partner for many other fish, particularly smoked and/or oily fish.
Although the hot peppery flavour is most pronounced when eaten raw, watercress can be cooked, and becomes the star ingredient in soup. Use my basic recipe for any Green Soup, adding two bunches of watercress right at the end. It also makes a fine sauce to serve with poached chicken, moving us away from winter roasts to a more delicate springtime feel – perfect with the first Jersey Royal potatoes. See Recipe.