Key Points of High-Yield Artificial Cultivation Techniques for Houttuynia cordata and a Detailed Explanation of Its Effects and Functions

Houttuynia cordata, also known as dog heart grass, folded ear root, and dog spot ear, is pungent, slightly cold, and slightly bitter. It is harvested in summer when the stems and leaves are lush and there are many flower spikes, then impurities are removed and it is sun-dried.So what are the high-yield cultivation techniques for Houttuynia cordata? What are its effects and functions?

What are the high-yield artificial cultivation techniques for Houttuynia cordata?

I. Plant Characteristics and Biological Properties

The Houttuynia cordata plant is 15-30 cm tall, with underground stems growing prostrate and white. The upper part of the stem is upright, while the base is creeping, purple-red, and hairless. The leaves are alternate, heart-shaped, 3-8 cm long and 4-6 cm wide, with an acute tip and entire margins; when old, the upper surface is slightly purplish, and the lower surface is purplish-red, with both surfaces hairless except along the veins; the petiole is 1-3 cm long and often sparsely hairy; the stipules are membranous, lanceolate, and connate with the petiole at the base to form a sheath. The spike inflorescence is borne at the upper end of the stem opposite the leaves, 1-3 cm long, with 4 white petal-like involucral bracts at the base, 1-2 cm long; the flowers are small and dense, bisexual, without a perianth, and the bracts are linear; there are 3 stamens with slender filaments; the pistil is composed of 3 carpels fused below, with a superior ovary and separate styles. The capsule is urn-shaped and splits at the top. The seeds are ovate and striped. The flowering period is from April to July, and the fruiting period is from June to September.

Houttuynia cordata originally grows in low, wet depressions, along ditches, and on field ridges. It has a relatively high water requirement and needs a sufficient water supply throughout the growing period to keep the soil moist; it grows better in warm, shady, and humid environments, is afraid of frost, and its underground stems are relatively cold-tolerant, able to overwinter below -15°C; it begins to sprout at 12°C, and the suitable growth temperature is 16-25°C; it has no strict requirements for soil or light, and soil rich in organic matter is best.

II. Site Selection, Land Preparation, and Application of Base Fertilizer

(1) Plot selection. In order to obtain a relatively high rhizome yield, the plot should be level, with sufficient water sources, convenient drainage and irrigation, a deep plow layer, suitable soil structure, good physical and chemical properties, and moderate fertility, and sandy loam soil should be chosen for planting.

(2) Fine land preparation. After selecting the plot, thoroughly remove weeds and the stalks of the previous crop, and deep plow and sun the soil. Before planting, deep plow and rake level, apply sufficient base fertilizer, and make the plot loose, fertile, and level.

(3) Apply sufficient base fertilizer. Before planting, apply 1000-1500 kg of decomposed farmyard manure and 150-200 kg of plant ash per mu, then plow once to a depth of 25-30 cm so that the fertilizer and soil are fully mixed.

(4) Make beds for planting. After the soil and fertilizer are fully mixed, make beds 2-2.5 m wide, with ditches 30-35 cm wide and 25-30 cm deep.

III. Propagation Methods

Houttuynia cordata generally uses asexual propagation, divided into rhizome propagation and cutting propagation, but rhizome propagation gives better results, saves time and labor, and produces a higher yield.

Rhizome propagation. Sowing can be done in all four seasons, but sowing in winter, spring, and early summer allows harvest in the same crop. The best sowing time is generally around the Beginning of Spring. Before the plants sprout new shoots, dig out the rhizomes, cut them into small sections 8-10 cm long with more than 2-3 axillary buds, and keep the fibrous roots. Open shallow furrows 5-8 cm deep at a row spacing of 20-25 cm, place the cut rhizomes in the furrows at a plant spacing of 8-10 cm, and cover with 6-10 cm of soil. If the soil is moist, no watering is needed; if the soil is dry, irrigate appropriately to keep the soil moist. After 15-20 days, seedlings can be seen emerging.

IV. Field Management

(1) Cultivation and weeding. After Houttuynia cordata is planted, weeds must be removed frequently. Before the rows close, soil can be hilled up and weeds removed; after the rows close, weeds should be pulled by hand, and fertilizer and water management should be combined with cultivation and weeding.

(2) Water and fertilizer management. Keep the soil moist throughout the growing period. In the early stage, growth is slow. From seedling survival until the rows close, apply 8-10 kg of urea per mu as a seedling fertilizer. During the vigorous growth period of stems and leaves, the fertilizer requirement is relatively large, so apply 10-15 kg of compound fertilizer per mu. After that, switch to foliar topdressing with a 0.4% potassium dihydrogen phosphate solution, sprayed once every 7 days for a total of 4-5 times. When the plant height is above 10 cm, hill up soil in time. During the entire growing period, do not irrigate with polluted dirty water, and prohibit the application of garbage, unfermented and undecomposed human (livestock) manure and urine, nitrate nitrogen (ammonium nitrate), etc. Do not apply any fertilizer within 30-35 days before harvest.

(3) Remove flower buds. When the aboveground part grows excessively, harvest the tender stems and leaves in time; when flowering and budding occur, remove the flower buds in time to avoid flowering consuming a large amount of nutrients and inhibiting the growth of underground stems.

(4) Pest and disease control: Houttuynia cordata rarely suffers from pests and diseases, and generally does not require chemical control. If root rot occasionally occurs, a 1000-fold solution of 70% thiophanate-methyl can be used for drenching.

V. Timely Harvest

For tender stems and leaves harvested for eating, harvest can be done from April to October, and multiple harvests are possible. For products based on underground stems, harvest can begin gradually after October according to market demand. After harvest, wash clean and tie into bundles for market. During storage and transport, water appropriately to keep fresh. During storage and transport, the product must be kept clean and hygienic. The interval from harvest to sale should not be too long, otherwise the rhizomes are likely to turn yellow, affecting the selling price.

Appendix: Effects and Functions

Houttuynia cordata is pungent in flavor and cold in nature. It can clear heat and detoxify, relieve pain, reduce swelling, and heal sores, promote urination and remove dampness, and strengthen the stomach and aid digestion. It is used to treat lung abscess, sores and swellings due to heat toxin, hemorrhoids with bloody stool, and accumulated heat in the spleen and stomach caused by excess heat, heat toxin, damp pathogens, and heat from disease.

Medicinal Value of Houttuynia cordata

1. Antibacterial

Modern research shows that its distinctive odor mainly comes from an active ingredient in the volatile oil of Houttuynia cordata——houttuynine (decanoyl acetaldehyde). Houttuynine is the main antibacterial component of Houttuynia cordata and has a clear inhibitory effect on Neisseria catarrhalis, Haemophilus influenzae, pneumococcus, Staphylococcus aureus, and others.

2. Diuretic

Houttuynia cordata also contains active ingredients such as quercitrin, which have antiviral and diuretic effects.

3. Anti-inflammatory

Clinical practice has proven that Houttuynia cordata has relatively good therapeutic effects on upper respiratory tract infections, bronchitis, pneumonia, chronic tracheitis, chronic cervicitis, whooping cough, and others, and also has a certain therapeutic effect on acute conjunctivitis, urinary tract infections, and others.

4. Enhance Immunity

Houttuynia cordata can also enhance the body's immune function, increase the phagocytic capacity of white blood cells, and has effects such as analgesia, relieving cough, stopping bleeding, promoting tissue regeneration, dilating capillaries, and increasing blood flow.

Nutritional Value of Houttuynia cordata

Houttuynia cordata mainly contains volatile oil, houttuynine (decanoyl acetaldehyde), and many other components. It has inhibitory and antibacterial effects on various pathogenic bacilli, cocci, influenza viruses, Leptospira, and others, and can improve the body's immune regulatory function.