How to grow fish mint (Houttuynia cordata)? Latest cultivation techniques and methods tutorial
Fish mint, also known as Houttuynia cordata, pig nostril, ji cai, dog ear etc., is a perennial herbaceous plant with persistent roots in the Saururaceae family, Houttuynia genus. It is both a medicinal and culinary plant, and the whole plant is edible. Its tender roots, tender stems and leaves are rich in nutrients and have a unique flavor. They contain protein, fat, carbohydrates, calcium, phosphorus and volatile oil and other nutrients, and have effects such as clearing heat and detoxifying, promoting diuresis and reducing swelling, and stopping bleeding. It has excellent edible value and medicinal value, and has been officially designated by the Ministry of Health of China as one of the resources with great development potential that is “both a medicine and a food”. In recent years, because of its good market returns, it has developed rapidly in Guangtong Town, playing an important role in promoting farmers' income growth and meeting people's consumption needs.
Morphological characteristics
The fish mint plant is semi-prostrate, with the upper part of the stem upright and the lower part creeping along the ground. The plant height is 15—60cm, sometimes slightly purple, with a fishy odor. The stem has obvious nodes, the lower part lies on the ground, and fibrous roots grow from the nodes, usually hairless; the underground rhizome is slender, creeping and spreading to reproduce, white, round in cross-section, with internodes 3—4.5cm long, and each node can both root and sprout; the leaves are simple and alternate, heart-shaped or round, commonly green, occasionally purple; the spike inflorescence is white or pale green, with a flowering period from May to June; the capsule is ovate, with a fruiting period from September to October.
Adaptable conditions
Fish mint prefers a warm and humid climate and has a wide temperature adaptation range. The underground stem can overwinter normally at -10—0°C. At 12°C the aboveground stem grows and seedlings emerge. The suitable temperature for the early growth stage is 16—20°C, and the suitable temperature for the underground stem maturation stage is 20—25°C. It grows well under shady and humid conditions and requires moist soil. The field soil water-holding capacity should be 75%—80%, and the relative air humidity should be 50%—80% for normal growth. It is not strict about light and can also grow and develop normally under weak light. It is not strict about soil conditions, but slightly acidic soil with a pH of 6—7, deep and fertile sandy loam is best.
Key cultivation points
1. Strong adaptability: Fish mint has strong adaptability and can grow in most soils. It can also be cultivated on barren slopes and poor thin soil. Generally, choose soil without “three wastes” pollution, with relatively deep soil layers, good water retention, strong air permeability and slight sandiness for cultivation, and crop rotation should be adopted appropriately.
2. Land preparation and bed opening: Before planting fish mint, remove weeds and residual roots, then plow, harrow and level the soil, and make beds about 1.30-1.60m wide with a bed spacing of about 33cm. Then open sowing furrows on the bed surface that are 13-15cm wide and 10-15cm deep, with a distance of 20cm between two sowing furrows. 3. Apply sufficient base fertilizer. Fish mint mainly uses rhizomes as the commodity, and its growth period is relatively long. The amount and quality of base fertilizer directly affect the yield of fish mint. Therefore, after leveling the plot, apply sufficient organic base fertilizer and phosphorus and potassium fertilizer in the sowing furrows. Apply 2500-4000kg of decomposed organic fertilizer (pen manure, compost), 50-70kg of calcium superphosphate, and 60-80kg of potassium chloride per mu.
3. Plot selection and land preparation and bed opening: For fish mint cultivation fields, choose soil with convenient transportation, deep and loose fertile layers, high organic matter content, slight acidity, and good water retention and air permeability, such as paddy fields, to achieve high yield and high quality. Before planting, plow and level the land, deep plow 20—30cm, remove weeds and residual roots, level it, and then open beds. The bed width is 1.3—1.5m. On the bed surface, open sowing furrows 12—15cm wide and 10—15cm deep, with a spacing of about 20cm between sowing furrows. The bed length depends on the plot, and the distance between two beds is about 35cm.
4. Seed stem selection and planting: Because the seed germination rate of fish mint is low, division propagation is generally used. At present there are two sowing methods: long stem sowing and short stem sowing. Long stem sowing requires a large amount of seed, so short stem sowing is often used in production. Select fresh, thick, pest-free, mature old stems as seed stems. Cut the selected seed stems at the internodes, each segment 4—6cm, retaining 2—3 nodes per segment. Before sowing, disinfect them in a 50% carbendazim 800-fold solution, then place them flat in the sowing furrows with a plant spacing of 5—8cm, cover with 5—6cm of soil. If the soil is dry, water to settle the roots. Cover the bed surface with a layer of plastic film or rice straw to keep the soil moist, increase soil temperature, and promote seed sprouting. The seed amount is 80—100kg per 667㎡.
5. Fertilization: Applying sufficient base fertilizer is the foundation for achieving high yield. Apply 2500—3000kg of organic fertilizer, 50kg of calcium superphosphate, and 25—30kg of potassium sulfate per 667㎡. Fish mint fertilization is mainly nitrogen and potassium, with less phosphorus. Potassium fertilizer is especially important for rhizome formation and improving aroma.
6. Cultivation management
① Weeding: After fish mint emerges, promptly remove weeds, diseased plants and weak plants to keep the land clean and reduce the occurrence of pests and diseases. At the same time, loosen the soil between plants and rows, but it should not be too deep; shallow cultivation is sufficient. Generally, before the rows close, carry out intertillage and weeding 2—3 times.
② Fertilizer and water management: Topdressing depends on the amount of base fertilizer applied and the plant growth condition. Early growth is slow. From seedling emergence to before row closure, apply 8—10kg/667㎡ of urea as seedling fertilizer. During the peak period of stem and leaf growth, the fertilizer requirement is relatively large, and 10—15kg/66㎡ of compound fertilizer can be applied as topdressing. After each harvest, a small amount of topdressing can be applied once. To improve the aroma and yield of artificially cultivated fish mint, carry out foliar topdressing in the middle and late growth stages, spraying 0.2%—0.3% potassium dihydrogen phosphate solution 2—3 times. Fish mint likes moisture and is not tolerant of drought, so pay attention to watering during drought to keep the soil moist and ensure normal growth and development. During the rainy season, pay attention to drainage and avoid water accumulation on the bed surface.
③ Pinching and removing buds: For plants whose aboveground stems and leaves grow too vigorously, pinch the tips to inhibit height growth, promote side branches, and earth up to protect the roots and promote underground stem growth, ensuring the stems are thick, white and tender. Removing buds can reduce nutrient consumption from flowering and promote underground stem growth.
④ Crop rotation: Because fish mint has good economic returns, some farmers plant it continuously after sowing to save effort, causing damage to soil structure, decreased fertility, serious pests and diseases, reduced yield, and even total crop failure. Adopting a crop rotation model, especially paddy-upland rotation, can effectively prevent continuous cropping obstacles.
Pest and disease control
Fish mint itself has a fishy smell and strong resistance to pests and diseases, so it is less prone to disease. However, in old planting areas, diseases and pests such as southern blight, purple blotch, black cutworm, and tobacco cutworm have appeared.
1. Southern blight: It mainly damages the stem base and underground stems of the plant. Before sowing, soak and disinfect seed stems with a 50% carbendazim 800-fold solution; in the early stage of the disease, dig out diseased plants with soil and destroy them, apply quicklime to disinfect the diseased area, and drench surrounding plants with a 40% dimethachlon wettable powder 800-fold solution or a 5% validamycin aqueous solution 1500-fold solution.
2. Purple blotch: When the plant disease incidence reaches 20%, spray 3% polyoxin water agent or 78% Kobo (Bordeaux mixture · mancozeb) wettable powder, once every 7—10d, 2—3 times.
3. Black cutworm: Before sowing, remove field weeds in time to eliminate some eggs and weed hosts; when the damaged plant rate reaches 10% or the insect density is relatively high, dissolve 50mL of 40.7% Lorsban (chlorpyrifos) in 1L of water, then evenly mix it into 5kg of chopped fresh vegetable leaves and evenly scatter it in the field in the evening; or use 0.25kg of 90% crystal trichlorfon mixed with 3kg of water, mix with 2.5kg of chopped fresh green grass or bran, and evenly scatter it in the field in the evening to trap and kill adults.
4. Tobacco cutworm: When the larval damage rate reaches 25%, spray with 4.5% beta-cypermethrin emulsifiable concentrate 2000-fold solution or 10% imidacloprid wettable powder 2500-fold solution, etc., once every 10d, for 2—3 consecutive times. For adults, use sugar : vinegar : white liquor : water = 6:3:1:10 plus an appropriate amount of trichlorfon to prepare a poisonous liquid and place it in the field to trap and kill them.
Harvesting and sales
There is no strict limit on the harvesting time of fish mint, and it can be harvested in batches. For fresh leaves and aboveground parts, fish mint can be harvested after growing for 25d. The leaves contain 20% volatile oil components and are relatively rich in houttuynin (decanoyl acetaldehyde) and manganese. They are nutritious when served as a cold dish or cooked in soup. When harvesting the underground parts, first cut off the aboveground parts, tie them in bundles by grade for fresh sale, or dry them in the sun for sale as medicinal material. After cutting off the stems and leaves, harvest the underground rhizomes, cover them with rice straw or other shading material to reduce water loss, clean the underground rhizomes, tie them in bundles by grade, and sell them on the market.