Watercress

Nasturtium officinale

1. Identification and origin

Nasturtium officinale W.T. Aiton is an aquatic plant of the family Brassicaceae, known as watercress. It is native to Europe and Western Asia, having spread widely to temperate and subtropical regions. It grows spontaneously in clean watercourses, springs and wetlands, and is also cultivated in hydroponic systems or continuous-flow channels.

2. Economic importance

Watercress is a vegetable of high nutritional value, prized for its content of vitamins, minerals and bioactive compounds. Fresh consumption in salads and culinary preparations drives demand. The crop has growing importance in intensive horticulture, especially in production systems with running or recirculated water, ensuring high sanitary quality.

3. Botanical characterisation

Perennial herbaceous plant, fast-growing, with hollow, creeping stems that root at the nodes. The leaves are compound, dark green and with a characteristic peppery flavour. The flowers are small, white and grouped in terminal inflorescences. The plant reproduces by seeds and, above all, by vegetative propagation through stolons. It develops best in clean, cold and oxygenated water.

4. Edaphoclimatic requirements

It requires moist or submerged environments, with running, clean and well-oxygenated water. It prefers mild temperatures, between 10–20 °C, being sensitive to excessive heat, which reduces vigour and favours premature flowering. It needs good water quality, with a low nutrient content and absence of contamination. In cultivation, a light substrate or hydroponic systems are used.

5. Main pests

• Aphids (Aphididae): deformations and transmission of viruses.
• Whitefly (Aleyrodidae): weakening and sooty mould.
• Slugs and snails: leaf damage in moist environments.
• Leaf miners (Agromyzidae): galleries in the leaves.
• Pests are more frequent in protected crops or those with low water circulation.

6. Main diseases

• Root and collar rots caused by Pythium and Phytophthora in contaminated water.
• Leaf spots caused by opportunistic fungi in conditions of high humidity and low circulation.
• Aquatic bacteria can cause wilting or necrosis when the water quality is poor.
• The maintenance of clean and moving water is essential to reduce the incidence of diseases.

7. General cultural management

It includes the use of clean and running water, rigorous control of water quality, removal of old plants, frequent harvesting to stimulate sprouting, pest monitoring and the maintenance of moderate temperatures. In hydroponic systems, it is essential to ensure adequate oxygenation and to avoid the accumulation of organic matter. The hygiene of the structures and the partial renewal of the water reduce sanitary risks.

Bibliographic references

• Dixon, G. R. (2007). Vegetable Brassicas and Related Crucifers. CABI.
• Schreiner, M., & Huyskens‑Keil, S. (2006). “Phytochemical changes in watercress during growth.” Journal of Applied Botany and Food Quality.
• Kays, S. J. (2011). Cultivated Vegetables of the World. Wageningen Academic Publishers.
• Rubatzky, V. E., & Yamaguchi, M. (2012). World Vegetables. Springer.
• FAO. Technical documents on the production of vegetables in hydroponic systems and aquatic environments.