Practical
Plants

Nasturtium microphyllum

Watercress

a perennial member of the Nasturtium genus in the family Brassicaceae.

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Taxonomy and growth

Life cycle
perennial
Height
0.5 m
Spread
1 m
Fertility
Self fertile, Bees, Flies, Self
Flower type
hermaphrodite
Pollinators
Bees, Flies, Self

Uses

Edible uses

This section contains historical Plants For A Future notes marked noncommercial.

Leaves - raw or cooked[4][13][16][17][1][9]. Exceptionally rich in vitamins and minerals, especially iron[5]. The leaves are mainly used as a garnish or as an addition to salads, the flavour is strong with a characteristic hotness[3]. The seed can be sprouted and eaten in salads[3]. A hot flavour. The seed is ground into a powder and used as a mustard[12][3]. 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[7].

Product or use
Condiment
Plant part
Leaves
Plant part
Seed

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

Antiscorbutic, diuretic, expectorant, purgative, stimulant, stomachic[11][17][6][12]. Use with caution[6].

Product or use
Antiscorbutic
Product or use
Diuretic
Product or use
Expectorant
Product or use
Purgative
Product or use
Stimulant
Product or use
Stomachic

Environment

Range
Europe, including Britain, to W. Asia.
Habitat
Stream margins, ditches, flushes etc with moving water[2][9], usually in chalk or limestone areas[14].
Light
full sun
Shade tolerance
no shade
Water
aquatic
Hardiness
Zone 6+
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

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[15]. Just put it in a container of water until the roots are well formed and then plant out in shallow water.

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

Watercress is easily grown when given the correct conditions of slowly flowing clean water, preferably coming from chalky or limestone soils[8]. It prefers to grow in water about 5cm deep[10] with an optimum pH 7.2[5]. 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[9][10]. Plants are hardy to about -15°c[5], they tolerate somewhat lower temperatures than the closely related N. officinale[5]. Watercress is often cultivated for its edible leaves, there are some named varieties[1][3]. The plant is very sensitive to pollution so a clean source of water is required[5]. 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[7]. Unfortunately, virus diseases have become more common in cultivated plants and so most propagation is carried out by seed[8]. This is a triploid species. It has hybridised naturally in the wild with the diploid species N. officinale to produce the sterile hybrid N. x sterilis which is also commonly cultivated as a salad crop[8]. The flowers are a rich source of pollen and so are very attractive to bees[16].

References

  1. Simons. New Vegetable Growers Handbook. Penguin 1977-00-00 ISBN 0-14-046-050-0

    ↩1↩2

  2. Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962-00-00

    ↩

  3. Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9

    ↩1↩2↩3↩4

  4. Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972-00-00 ISBN 0-486-20459-6

    ↩

  5. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2↩3↩4↩5

  6. Lust. J. The Herb Book. Bantam books 1983-00-00 ISBN 0-553-23827-2

    ↩1↩2

  7. Bown. D. Encyclopaedia of Herbs and their Uses. Dorling Kindersley, London. 1995-00-00 ISBN 0-7513-020-31

    ↩1↩2

  8. Phillips. R. & Rix. M. Vegetables Macmillan Reference Books, London. 1995-00-00 ISBN 0 333 62640 0

    ↩1↩2↩3

  9. Vilmorin. A. The Vegetable Garden. Ten Speed Press ISBN 0-89815-041-8

    ↩1↩2↩3

  10. Thompson. B. The Gardener's Assistant. Blackie and Son. 1878-00-00

    ↩1↩2

  11. Grieve. A Modern Herbal. Penguin 1984-00-00 ISBN 0-14-046-440-9

    ↩

  12. Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959-00-00

    ↩1↩2

  13. Mabey. R. Food for Free. Collins 1974-00-00 ISBN 0-00-219060-5

    ↩

  14. Larkcom. J. Salads all the Year Round. Hamlyn 1980-00-00

    ↩

  15. Muhlberg. H. Complete Guide to Water Plants. E. P. Publishing Ltd. 1982-00-00 ISBN 0-7158-0789-7

    ↩

  16. Chiej. R. Encyclopaedia of Medicinal Plants. MacDonald 1984-00-00 ISBN 0-356-10541-5

    ↩1↩2

  17. Launert. E. Edible and Medicinal Plants. Hamlyn 1981-00-00 ISBN 0-600-37216-2

    ↩1↩2

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