Detailed Explanation of Key Points for Artificial Cultivation of Houttuynia cordata

Houttuynia cordataAlso known as zhe'ergen, jicai, choucao, yulincao, goutie'er, etc., it is a perennial herbaceous plant of Houttuynia in the Saururaceae family. It is cold in nature, pungent and bitter in taste, and has antibacterial, antiviral, heat-clearing and detoxifying effects. It has both edible and medicinal value.

I. Growth Habits and Environmental Requirements. Under natural conditions, it often grows wild in shady mountain areas, along forest edges and roadsides, and in grass at the edges of ditches and low-lying wet areas. It prefers a warm and humid climate and grows well under shady and moist conditions. It is averse to drought and has a wide adaptability to temperature. Its underground stems overwinter and will not be killed by -10 to 0°C. When the temperature is 12°C, the underground stems grow and can sprout. The early growth stage requires 16 to 20°C, and the underground stem maturation stage requires 20 to 25°C. Houttuynia cordata prefers moisture and tolerates waterlogging, requiring moist soil, with field soil water-holding capacity of 75% to 80%. The soil should be slightly acidic, pH 6 to 7. It has no strict soil requirements, and fertile sandy loam and humus loam are best, but clayey soil can also support its growth. Fertilization is mainly nitrogen-based, with appropriate application of phosphorus and potassium fertilizers. Under conditions of sufficient organic matter, the underground stems grow thick and strong.

II. Land Selection and Bed Preparation. Choose plots with loose, fertile soil and convenient drainage and irrigation. If using paddy fields, plow and sun the field in winter, apply 2000 to 4000 kg of decomposed organic fertilizer and 25 kg of compound fertilizer per 667 sq m, then plow, crush and level the soil. Make beds 1.3 to 1.5 m wide and 30 cm high, with length determined by the terrain, and ditch spacing of 30 to 40 cm. Plant on the bed surface.

III. Planting. Houttuynia cordata can be propagated by seeds, but root division propagation is more commonly used. Planting can be done in spring or autumn, but spring is better. Planting methods can be hole planting or furrow planting. Apply organic fertilizer into the holes or furrows, cover with 2 to 3 cm of fine soil, select pest-free, robust underground stems and cut them into 4 to 6 cm short sections, each with 2 to 3 nodes, place them flat in the planting holes or furrows at a plant spacing of 5 to 8 cm, then cover with soil about 5 to 6 cm thick. If the soil is dry, spray water to settle the roots and keep the soil moist.

IV. Fertilization. Fertilization for Houttuynia cordata is mainly nitrogen and potassium, with less phosphorus required, but it must not be lacking. When the seedlings emerge to a height of about 3 cm, the first topdressing can be applied. Use 1 part decomposed human manure and urine mixed with 4 to 5 parts water, plus 2% urea in the manure liquid for watering. In the middle and late stages, production enters the vigorous growth period, and fertilizer demand increases accordingly. While ensuring nitrogen fertilizer, apply phosphorus and potassium fertilizers in combination, especially potassium fertilizer, which is particularly important for rhizome formation.

V. Field Management. In Houttuynia cordata production, intertillage and weeding should be carried out together with fertilization. Field management should be strengthened in the middle and late stages. The soil should be kept moist throughout the growing period. Water timely during drought, and drain accumulated water promptly during the rainy season. Weed and loosen the soil before row closure. After row closure, combine promotion and control. When the aboveground parts grow excessively, promptly pick tender stems and leaves. When the aboveground stems and leaves turn yellow and become thin and small, apply appropriate topdressing to promote tillering. If the plants are not being kept for seed, promptly remove emerging flower buds to avoid consuming large amounts of nutrients through flowering.

VI. Pest and Disease Control. The stems and leaves of Houttuynia cordata all have a fishy odor, so there are rarely insect pests, but diseases include southern blight and leaf spot. Control methods:

1. Choose rational crop rotation, preferably paddy-upland rotation;

2. Choose soil with convenient drainage and irrigation that is loose and fertile;

3. Strictly select seed stems and remove diseased seed stems.

4. Strengthen field management. Pay attention to drainage during continuous rainy seasons and irrigation during drought;

5. In the early stage of disease onset, choose mancozeb, chlorothalonil, thiophanate, etc. for spraying or root drenching.

7. Harvesting. Houttuynia cordata can be dug for consumption throughout the year. Pick tender stems and leaves in spring and summer, and dig underground stems in autumn and winter. Artificially cultivated Houttuynia cordata can be harvested 2 to 3 times for tender stems and leaves. One week after each harvest, apply diluted human manure and urine or biogas slurry plus an appropriate amount of nitrogen-phosphorus-potassium compound fertilizer. When harvesting underground stems, leave a portion or cut stems. When the temperature rises the following year, they will sprout and emerge. Promptly carry out weeding, soil loosening, thinning, topdressing, and other management. In this way, continuous production can be maintained for many years.