Origin:
Nasturtium officinale Ait. f. var. microphyllum (Boenn. ex Reichenb.) Thellung, commonly referred to as watercress, is a member of the Brassicaceae family and is native to Europe and Asia. It is believed to have originated in Persia and has been cultivated for thousands of years.
Common Names:
Watercress has several common names such as curly cress, true watercress, yellowcress, and American cress. In some parts of the world, it is also known as land cress, because it can be grown on dry land instead of water.
Uses:
Watercress has a long history of medicinal and culinary uses. The plant is packed with essential nutrients, vitamins, and minerals like vitamins A, C, and K, calcium, potassium, and iron. Due to its high nutrient content, it is considered a superfood and is often used in salads, sandwiches, soups, and smoothies. It is also a popular ingredient in traditional medicines and is known to have antibacterial, antiviral, and anti-inflammatory properties.
General Appearance:
Watercress is a perennial herb that grows best in cool, running water. It has small, round, and peppery-flavored leaves that are arranged in pairs and are dark green in color. The leaves and stems can grow up to 50 cm long and are covered in small hairs. The plant produces small, white, or pink flowers that bloom in the summer months. Watercress is a fast-growing plant that can reach maturity in as little as six weeks.
Light Requirements
Nasturtium officinale Ait. f. var. microphyllum typically requires partial to full sun exposure for optimal growth. In areas with hot climates, partial shade is preferred to prevent wilting and scorching of the leaves and stems. It is essential to provide adequate sunlight for maximum chlorophyll production, and thereby guarantee healthy foliage and better flower production.
Temperature Requirements
The ideal temperature range for the growth of Nasturtium officinale Ait. f. var. microphyllum is between 10°C to 25°C. The plant can tolerate cold temperatures, but prolonged exposure to frost can damage the plant. High temperatures can also affect the plant's growth, causing the leaves to wilt and reducing the quality of the plant's yield. The plant requires a moderate temperature throughout the year for optimal growth.
Soil Requirements
The plant grows best in moist and well-drained soils. The ideal pH range for the growth of Nasturtium officinale Ait. f. var. microphyllum is between 6.5 to 7.5. The soil should be rich in organic matter to ensure proper nutrient availability. The plant should be grown in areas devoid of weed growth to avoid competition for water and nutrients. The soil texture should also be loose, which promotes good aeration and water penetration. The plant can tolerate slight soil salinity up to a certain level but excessive salinity can significantly slow down growth.
Cultivation Methods
Nasturtium officinale Ait. f. var. microphyllum (Boenn. ex Reichenb.) Thellung, commonly known as watercress, is a fast-growing aquatic or semi-aquatic plant that thrives in moist soils, shallow streams, and marshlands. To cultivate watercress, you need to ensure that you have a constantly moist environment, preferably near a reliable source of water. You can plant watercress in containers or baskets placed in shallow water. You can also plant it on the soil, but you need to ensure that the soil remains moist at all times.
Watering Needs
Watercress needs a constant supply of clean water to thrive. It requires frequent watering, especially during hot weather. Watercress can tolerate partial shade, but it grows best in full sun. Ensure that you water the plants regularly, especially during the dry months to avoid drying out.
Fertilization
Watercress is a nutrient-demanding plant that requires regular feeding for optimal growth. You can use organic compost or commercial fertilizers to provide the necessary nutrients. Avoid using fertilizers that are high in nitrogen as they can cause lush foliage growth at the expense of the roots. Instead, use balanced fertilizers that provide equal amounts of nitrogen, potassium, and phosphorus.
Pruning
Pruning watercress is essential to maintain its growth and health. It helps to remove old and diseased leaves, improving air circulation and reducing the risk of pest infestation. You can prune watercress by cutting the tips of the long stems or by removing the entire stem above the waterline. This will stimulate new growth, ensuring a constant supply of fresh leaves.
Propagation of Nasturtium officinale Ait. f. var. microphyllum (Boenn. ex Reichenb.) Thellung
Nasturtium officinale Ait. f. var. microphyllum (Boenn. ex Reichenb.) Thellung, commonly known as Watercress, can be easily propagated by various methods. Here are some of the most common methods used for propagating Watercress:
Seeds
The most common method of propagating Watercress is through seeds. The seeds should be sown in early spring, in a seed tray filled with a mixture of compost and sand. The seeds should be sprinkled on top of the soil and then covered lightly with more soil. Keep the soil moist by misting it regularly. The seeds will germinate in about 7 to 10 days.
Cuttings
Another method of propagating Watercress is by taking cuttings. Cut a stem from the parent plant about 4 to 6 inches long and remove the bottom leaves. Place the cutting in a glass of water and put it in a bright but shady spot. Change the water every day or two. After about 7 to 10 days, roots will start to develop, and the cutting can be planted in soil once the roots are 1 to 2 inches long.
Division
Watercress can also be propagated by dividing the parent plant. This should be done in the spring or fall. Dig up the parent plant and gently separate the clumps. Replant the clumps in the soil at the same depth they were growing before. Water them well and keep the soil moist until new growth appears.
Disease Management
Nasturtium officinale Ait. f. var. microphyllum is susceptible to various diseases. Some of the common diseases that may affect the plant include:
- Downy mildew: This is a fungal infection that causes yellow spots on leaves. It can be controlled by using fungicides.
- Pythium root rot: This is a soil-borne fungal disease that leads to root rot. To manage it, avoid overwatering and use well-draining soil.
- Fusarium wilt: This is a soil-borne fungal disease that causes yellowing and wilting of leaves. It can be managed by removing infected plants and using fungicides.
Pest Management
Nasturtium officinale Ait. f. var. microphyllum is also susceptible to pest attacks. Some common pests that may affect the plant include:
- Aphids: These tiny insects suck the sap from the plant, leading to stunted growth and yellowing of leaves. They can be controlled by using insecticidal soap or neem oil.
- Slugs and snails: These pests feed on the leaves and stems of the plant and can be controlled by handpicking or by using baits.
- Whiteflies: These tiny pests feed on plant sap, leading to stunted growth and yellowing of leaves. They can be controlled by using insecticidal soap or neem oil.
