What to know about Nasturtium officinale (watercress) before using it medicinally

Nasturtium officinale, commonly known as watercress, is a nutrient-rich herb that has been valued for centuries for its ability to improve overall health, boost the immune system, and combat various diseases due to its high levels of vitamins, minerals, and antioxidants.

From a horticultural perspective, Nasturtium officinale is a fast-growing, cold-hardy annual that thrives in moist environments and can be harvested continuously, making it an ideal crop for home gardens and commercial agriculture. From a botanical standpoint, this herb belongs to the Brassicaceae family and is characterized by its pungent, peppery flavor and its delicate, round leaves.

Historically, Nasturtium officinale has been used for centuries in traditional medicine, with references to its use dating back to ancient Greece and Rome, where it was prized for its medicinal and culinary properties.

This article explains the medicinal, horticultural, botanical, and historical aspects of Nasturtium officinale.

What are the medicinal properties of Nasturtium officinale?

Nasturtium officinale helps with various health issues, including inflammation, antimicrobial properties, and antioxidant activity. It also supports cardiovascular health by reducing blood pressure and cholesterol levels. Additionally, it may help in reducing cancer risk and improving cognitive function.

The active constituents of Nasturtium officinale include flavonoids, alkaloids, and glucosinolates, which are responsible for its medicinal properties. These compounds have been shown to exhibit anti-inflammatory, antimicrobial, and antioxidant activities, making the plant a potential therapeutic agent for various health conditions.

The parts of the plant most used for medicinal purposes are its leaves, stems, and roots. The leaves are rich in vitamins and minerals, while the stems and roots contain a higher concentration of flavonoids and alkaloids. These plant parts have been traditionally used in herbal medicine to treat various health conditions, including digestive issues and skin problems.

Improper use of Nasturtium officinale may lead to side effects such as allergic reactions, digestive issues, and interactions with certain medications. Excessive consumption of the plant may cause nausea, vomiting, and diarrhea, while long-term use may lead to kidney damage and bleeding disorders.

To use Nasturtium officinale medicinally, it is essential to exercise caution and follow proper guidelines. Pregnant and breastfeeding women, as well as individuals with kidney disease, should consult a healthcare professional before using the plant. Additionally, individuals with allergies or sensitivities to other plants in the Brassicaceae family should avoid using Nasturtium officinale.

What are the horticulural aspects of Nasturtium officinale?

Nasturtium officinale grow best in moist, fertile soils with a pH between 6.0 and 7.0. They require partial shade to full sun and a consistent water supply. The optimal temperature for growth is between 15°C and 20°C. Watercress is a fast-growing crop, requiring frequent watering.

Planting tips for Nasturtium officinale include selecting a location with consistent moisture and providing a nutrient-rich soil mix. Sow seeds thinly and evenly, 1-2 cm deep, in late spring or early summer. Water gently but thoroughly after sowing. Thin seedlings to 5-10 cm apart to prevent overcrowding.

Harvesting watercress typically begins 20-30 days after sowing, when leaves are 5-7 cm long. Pinch or cut off individual leaves or harvest the entire plant by cutting the stem near the base. Harvesting watercress in the morning, when the leaves are at their highest water content, is ideal. Harvesting continuously encourages the plant to produce new leaves.

Common pests affecting Nasturtium officinale include aphids, slugs, and snails, which damage leaves and stems. Fungal diseases like downy mildew and root rot can also affect watercress, often caused by overwatering or poor soil drainage. Regularly inspecting the crop and controlling pest populations can prevent damage to the plant.

What are the botanical aspects of Nasturtium officinale?

Nasturtium officinale is an annual or biennial plant belonging to the Brassicaceae family. It has a spreading habit, with delicate stems and leaves that are 2-10 cm long, pinnately lobed, and have a distinctive peppery odor. The leaves are often variegated with white or yellow.

Nasturtium officinale is classified as Nasturtium officinale (R. Br.) R. Br. in the kingdom Plantae, phylum Magnoliophyta, class Magnoliopsida, order Brassicales, family Brassicaceae, subfamily Brassicoideae, tribe Brassiceae, and genus Nasturtium. It has two recognized subspecies.

Several variants of Nasturtium officinale exist, including 'Alaska', 'Red Emperor', and 'Green Wave', which are grown for their different leaf colors and flavors. Some cultivars are resistant to downy mildew, which is a common disease affecting watercress.

Nasturtium officinale is native to Europe, Western Asia, and North Africa, but it has been naturalized in many other regions worldwide. It can be found growing wild in riparian areas, and is often cultivated in gardens and used as a salad green.

The life cycle of Nasturtium officinale consists of germination, seedling growth, rosette formation, stem elongation, and flowering. It typically germinates in spring or autumn, and can complete its life cycle in as little as 30 days.

What are the historical aspects of Nasturtium officinale?

Nasturtium officinale is a plant with a long history of culinary and medicinal use. Ancient Greeks and Romans used it to flavor food, while medieval Europeans used it to treat ailments such as gout and kidney stones.

In ancient Greek and Roman mythology, watercress was associated with the goddess Aphrodite, who was said to have used it as a food offering to her lover. Watercress was also linked to the myth of the nymph, Chione, who was turned into a watercress by the god, Poseidon.

In the language of flowers, watercress is a symbol of good health, wealth, and fertility. It is also associated with the qualities of purity, vitality, and renewal. The plant's peppery flavor and aroma are believed to have healing properties, making it a popular choice for salads and as a garnish.

Historical texts such as Pliny the Elder's "Naturalis Historia" and the 16th-century herbal, "The Herbal of Galen", document the medicinal uses of watercress. The plant's leaves, seeds, and stems were used to treat a variety of ailments, from digestive issues to skin conditions.

Archaeological finds have revealed the importance of watercress in ancient cultures. Excavations at Roman sites have uncovered evidence of watercress cultivation, while ancient Greek pottery has been found with watercress motifs. Watercress seeds have also been discovered in Egyptian tombs, where they were used as offerings to the dead.