Nasturtium officinale - Watercress

Family:	Cruciferae
Habit:	Perennial
Height:	0.5
Width:	1
Synonyms:	Rorippa nasturtium-aquaticum. (L.)Hayek. Sisymbrium nasturtium-aquaticum.
Range:	Europe, including Britain, from Sweden and Denmark south and east to N. Africa and W. Asia.

Nasturtium officinale (Watercress) is a Perennial which grows to a height of 0.5m and a width of 1m . It has a hardness rating of 6and is vunerable to frost.
Watercress will flower in November to April. the seeds ripen from January to April
The flowers from this plant are hermaphrodite (has both male and female organs) and they are pollinated by Bees, flies, self

Soil Information

Watercress will grow in light (sandy),medium (loamy),hard (clay) soil. It is not necessary for the soil to be well drained.
The soil prefers the following PH / acid levels :
- pH of less than 6, Acidic soils
- pH between 6 and 8, Neutral soils
- pH greater than 8, Basic soils
Watercress prefers soils

Ideal Planting Locations

Watercress should not be planted in shady areas.

Stream margins, ditches, flushes etc with moving water[17, 27], usually in chalk or limestone areas[52].

Planting places suited to this plant described below.

• Is a pond plant
• A bog garden plant

Cultivation Details

Watercress is easily grown when given the correct conditions of slowly flowing clean water, preferably coming from chalky or limestone soils[264]. It prefers to grow in water about 5cm deep[37] with an optimum pH 7.2[200]. Plants can be grown in wet soil if the position is somewhat shaded and protection is given in winter, though the flavour may be hotter[27, 37]. Hardy to about -15°c[200]. Watercress is often cultivated for its edible leaves, there are some named varieties[16, 183]. The plant is very sensitive to pollution so a clean source of water is required[200]. Plants will often continue to grow all through mild winters. A fast-growing plant, the stems trail along the ground or float in water and produce new roots at the leaf nodes, thus making the plant very easy to propagate vegetatively[238]. Unfortunately, virus diseases have become more common in cultivated plants and so most propagation is carried out by seed[264]. This is a diploid species. It has hybridised naturally in the wild with the triploid species N. microphyllum to produce the sterile hybrid N. x sterilis which is also commonly cultivated as a salad crop[264]. The flowers are a rich source of pollen and so are very attractive to bees[7].

Edible Uses*

* See disclaimer
Edible Rating: 4/5
Leaves - raw or cooked[2, 5, 7, 9, 16, 27]. Water cress is mainly used as a garnish or as an addition to salads, the flavour is strong with a characteristic hotness[183]. It has a reputation as a spring tonic, and this is its main season of use, though it can be harvested for most of the year and can give 10 pickings annually[238]. Some caution is advised if gathering the plant from the wild, see the notes above on toxicity. The leaves are exceptionally rich in vitamins and minerals, especially iron[200]. A nutritional analysis is available[218]. The seed can be sprouted and eaten in salads[183]. A hot mustardy flavour[K]. The seed is ground into a powder and used as a mustard[46, 183]. The pungency of mustard develops when cold water is added to the ground-up seed - an enzyme (myrosin) acts on a glycoside (sinigrin) to produce a sulphur compound. The reaction takes 10 - 15 minutes. Mixing with hot water or vinegar, or adding salt, inhibits the enzyme and produces a mild but bitter mustard[238].

• Condiment - the various plants that are used as flavourings, either as herbs, spices or condiments.
• Leaves -
• Seed - includes nuts, cereals, peas and beans.

Medicinal Uses*

* See disclaimer
Medicinal Rating: 3/5
Watercress is very rich in vitamins and minerals, and has long been valued as a food and medicinal plant[254]. Considered a cleansing herb, its high content of vitamin C makes it a remedy that is particularly valuable for chronic illnesses[254]. The leaves are antiscorbutic, depurative, diuretic, expectorant, purgative, hypoglycaemic, odontalgic, stimulant and stomachic[4, 7, 9, 21, 46, 222, 238]. The plant has been used as a specific in the treatment of TB[4]. The freshly pressed juice has been used internally and externally in the treatment of chest and kidney complaints, chronic irritations and inflammations of the skin etc[9]. Applied externally, it has a long-standing reputation as an effective hair tonic, helping to promote the growth of thick hair[244]. A poultice of the leaves is said to be an effective treatment for healing glandular tumours or lymphatic swellings[244]. Some caution is advised, excessive use of the plant can lead to stomach upsets[9, 21]. The leaves can be harvested almost throughout the year and are used fresh[238].

• Antiscorbutic - A plant rich in vitamin C that is used to counteract scurvy.
• Depurative - Eliminates toxins and purifies the system, especially the blood.
• Diuretic - Acts on the kidneys, promoting the flow of urine.
• Expectorant - Clears phlegm from the chest by inducing coughing.
• Hypoglycaemic - Reduces the levels of sugar in the blood.
• Odontalgic - Treats toothache (temporary measure only) and other problems of the teeth and gums.
• Purgative - A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.
• Stimulant - Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.
• Stomachic - Aids and improves the action of the stomach.
• TB - Plants used in the treatment of tuberculosis

Propagation

Seed - sow spring in a pot emmersed to half its depth in water. Germination should take place within a couple of weeks. Prick out seedlings into individual pots whilst they are still small and increase the depth of water gradually until they are submerged. Plant out into a pond in the summer. Cuttings can be taken at any time in the growing season. Virtually any part of the plant, including a single leaf, will form roots if detached from the parent plant[56]. Just put it in a container of water until the roots are well formed and then plant out in shallow water.

Known Hazards

Whilst the plant is very wholesome and nutritious, some care should be taken if harvesting it from the wild. Any plants growing in water that drains from fields where animals, particularly sheep, graze should not be used raw. This is due to the risk of it being infested with the liver fluke parasite[5, 244]. Cooking the leaves, however, will destroy any parasites and render the plant perfectly safe to eat[244].

Other Uses

The juice of the plant is a nicotine solvent and is used as such on strong tobaccos[7].

• Hair - Plants used as hair shampoos, tonics, to treat balding etc.
• Miscellany - A rag-bag of items that are difficult to categorise.

Cultivars

'Improved Broad-Leaved' - This form has large, broad, oval leaves and a mildly pungent flavour[183].

References

Flora of the British Isles.
Clapham, Tootin and Warburg.
Author: Clapham, Tootin and Warburg.
Rating:
Publisher : A very comprehensive flora, the standard reference book but it has no pictures.
Date of Publication : 1962

The New RHS Dictionary of Gardening. 1992.
Huxley. A.
Author: Huxley. A.
Rating:
Publisher : Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
Date of Publication : 1992

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