Nasturtium officinale, or watercress is a member of the brassica, or cabbage family. Unlike may other members of this large family, watercress does not seem to be troubled by the caterpillars of the common white butterfly. Watercress is one of the oldest known leaf vegetables to be consumed by humans and has a mild peppery tangy flavour when eaten raw as a salad vegetable.

This peppery flavour completely dissapears with cooking and the plant is delicious when stir-fried with a little butter. When cooking it you need a large amount of the raw plant as it cooks down to about a quarter of the original volume. It is said to possess many health benefits and contains fairly high amounts of calcium, iron, folic acid and vitamins A and C.

Like other brassica, watercress foliage becomes bitter when the plant flowers. Watercress, as the name suggests, grows where there are copious supplies of moisture, usually along the edge of small streams, where its hollow stems float on the surface, keeping the leaves clear of the water.

Being aquatic, it is an ideal plant to grow hydroponically but it can be grown in soil in a garden as long as it has regular and large supplies of water kept up to it. It will definitely not grow in stagnant water. It has long been grown commercially in Europe, where it is available pre-packed and as a salad vegetable.

Although it is not often grown in the home vegetable garden it is possible to produce enough for home consumption without having a stream flowing through your property, although that is of course helpful. It can be grown in in large deep containers such as a set of old concrete washtubs, stock troughs, half mussel floats or an old bathtub.

Watercress needs to be grown in a warm, sheltered site wirth no overhanging trees, where it will recieve the maximum amount of sunlight. A 15cm layer of well-rotted compost should be covered with another 10cm  of rich soil and the lot compressed and then covered with with about 5cm of fine pea-gravel. Cuttings collected form wild plants can then be inserted in the soil to a depth of about 4cm to 5cm. The best cutting are about 10cm long, cut squarely just below a leaf and the bottom half stripped of any foliage.

These should be inserted about 7cm to 8cm apart, keeping well watered and shaded heavily from the sun, not excluding air until all cuttings are well rooted.  Once cuttings start to grow, the container can be gently flooded so that the tips are just above the water. A bung in the side of the container at the same level as the top of the gravel can be opened and the water changed at least once a week, preferably more.

If you are lucky enough to have permanent running water on your porperty then it is not a difficult matter to construct a trough where water flows in one end and trickles out the other. It is said that watercress does better in slightly alkaline water.

When harvesting watercress, pick only the young tender tips with a sharp knife. It may be hassle to grow watercress properly but it is a very nutritious and tasty vegetable and it delicious as salad or cooked.. It can also be made into a tasty soup.

Article sourced from Fairfax Media. 7th may, 2009