How to Grow Watercress? Cultivation Techniques and Management Essentials Explained
Watercress originates from Europe and is a perennial aquatic herb in the genus Nasturtium of the Brassicaceae family, also known as watercress, water field mustard, water cress, etc. It is cultivated in Heilongjiang, Hebei, Shanxi, Shandong, Henan, Anhui, Jiangsu, Guangdong, Guangxi, Shaanxi, Sichuan, Guizhou, Yunnan, Xizang and other regions of China. Let's take a look at watercress cultivation techniques below!
Growth Habits of Watercress
Watercress prefers cool and humid environments. The suitable growth temperature is 15-25°C, with the optimum temperature being around 20°C. Growth is slow below 10°C. It can tolerate multiple short periods of frost. In winter, when the temperature is around 0°C, it can safely overwinter in open fields. If the temperature exceeds 30°C, growth stagnates and leaves tend to turn yellow or wither. During the growing period, good light is required. When light is insufficient, stems and leaves grow weakly and yields are low. It prefers neutral loam soil with strong water and fertilizer retention, with a suitable pH of 6.5-7.5.
Cultivated Varieties of Watercress
1. Guangdong Small-leaf Watercress: Small-leaf type, plant height 30-40 cm, stem diameter about 0.9 cm, 2-3 pairs of lateral leaflets, terminal leaflet ovate, 2.6 cm long and 2.2 cm wide, brown. It blooms in late April but does not set seed, so it can only be propagated vegetatively.
2. British Large-leaf Watercress: Large-leaf type, plant height 40-50 cm, stem diameter about 0.79 cm, 1-3 pairs of lateral leaflets, terminal leaflet round or nearly round, 3.2 cm long and 3.4 cm wide, green. It has strong cold resistance and does not change color under low temperatures and in winter.
3. Jiangxi Large-leaf Watercress: Large-leaf type, plant height about 40 cm, stem diameter about 0.75 cm, 1-3 pairs of lateral leaflets, terminal leaflet long ovate, 3 cm long and 1.6 cm wide. The leaves are green with red veins and do not change color in winter or under low-temperature conditions.
Propagation Techniques of Watercress
1. Seed propagation: Watercress seed propagation is mostly sown and raised from early September to late September when the temperature drops to 20-25°C. It can be divided into dryland seedling raising and semi-paddy seedling raising. When the seedlings reach 4-5 cm in height, irrigate to maintain a thin layer of water on the bed surface. As the seedlings grow, gradually deepen the water layer to 1.5-2 cm.
2. Cuttage propagation: Watercress cuttage development is mostly carried out in mid-September. When the temperature drops to around 25°C, cut tender stems about 15 cm long from the middle and upper parts of the plants in the seedling field, and transplant them into a field that has been previously plowed, harrowed and leveled for propagation. When the seedlings grow to 15-20 cm tall, lift the seedlings and transplant them to the main field.
Cultivation Techniques of Watercress
1. Timely planting: In the Yangtze River Basin, planting is mostly done in mid-October. Before planting, select healthy seedlings with relatively thick stems, short internodes and complete green leaves. The stem base of watercress plants grows semi-prostrate and often has a distinction between sunny and shady sides. When planting seedlings, place the sunny side facing up and plant the two basal nodes together with the root system at a slant to promote survival. Row spacing 15 cm, hole spacing 10 cm, 2-3 plants per hole.
2. Land preparation and fertilization: Choose paddy fields with relatively low terrain, convenient drainage and irrigation, and fertile, loose soil for planting. Before planting, plow and harrow in shallow water. Combined with plowing, apply 3000 kg of human manure or 5000 kg of barnyard manure per mu as base fertilizer. After plowing, harrow finely and level the surface. Planting can be done while keeping the field muddy or with a thin layer of shallow water. For semi-dryland planting, apply base fertilizer, level the land, and open beds, keeping the soil moist for planting.
3. Water management: For semi-dryland planting, water thoroughly after planting. In the early stage, weeds tend to grow in the field, so weed in time. After that, water once every 3-4 days. If planting in paddy fields, maintain a 1-2 cm water layer in the early stage. As the plants grow, gradually deepen the water level to 3-4 cm, but it should not exceed 5 cm to prevent rusting of the roots.
4. Reasonable fertilization: Watercress can be harvested 30-40 days after planting. After each harvest, apply a quick-acting fertilizer promptly. Generally, broadcast 15 kg of urea per mu or spray 0.5% urea solution on the leaves. Alternatively, use 1200 kg of decomposed manure per mu, dilute with 5 times water, and apply as a liquid. Fertilization time should preferably be in the morning or evening.
5. Timely harvesting: After planting, harvest when the plant height reaches about 25 cm. There are two harvesting methods. One is to pick tender shoots plant by plant, then bundle them in bunches, which is relatively labor-intensive. The other is to harvest level with the mud, cutting three-quarters of the whole field each time, treading the old roots into the mud, then applying fertilizer and raking level, and replanting the remaining one-quarter of the seedlings.
6. Pest and disease control: Watercress has relatively strong adaptability and few pests and diseases during cultivation and production. The main insect pests include aphids, diamondback moths and striped flea beetles, which can be controlled with dimethoate, Bt, fenvalerate, etc. Diseases include leaf blight and rust. For leaf blight, spray mancozeb or chlorothalonil solution; for rust, spray triadimefon solution.