Houttuynia, scientific name Houttuyniacordata Thunb. , which is a flank root, is a perennial herb of the Sabahaceae family. It has a slight pungent, cool nature and enters the lungs. It has a significant inhibitory effect on influenza viruses and pneumococci. It has heat, detoxification, diuresis, analgesia, cough, and drive , Shun Qi, stomach and other effects. Its tender stems and leaves are delicious after cold or soup, and regular meals can prevent various diseases such as flu, pneumonia and eczema. It is a kind of health food that combines both medicine and food. Huize County has a long history of cultivation and consumption of Houttuynia cordata. Its annual cultivation area is about 200 hectares, and its total output value is 7.5 million yuan. The products are sold throughout the country through the wholesale markets in Kunming and other places and enjoy a high reputation. The pollution-free cultivation techniques are summarized below for reference. First, the election site preparation 1. The land selection is selected from flat land, abundant water sources, convenient drainage and irrigation, deep tillage layer, suitable soil structure, good physicochemical properties, and moderate fertility. It meets the requirements of GB/T 18407.1-2001 and the soil is loam or sandy loam. 2. After the land is finely sorted, the weeds and gravel are thoroughly removed and the sunburn is cultivated. Before the planting, the ploughs were turned and the basal fertilizer was applied to make the plot loose, fertile and flat. 3. Before planting basal fertilizer, uniform spreading of farmyard manure 4000--5000kg, ash 150--200kg (or 15kg of potassium sulfate) per 667m2, and ploughing 1 time, depth 25--30cm, fertilizer The soil is fully mixed. 4. Science works for the sake of local conditions. It is made impotence in low-lying and cold-dipping lands. The heights are made flat and the width is 1.5--2m. Second, cultivation technology Planting time is usually planted after the end of spring frost. 2. Breeding methods generally use underground stems for asexual reproduction. 3. Planting methods Select the rich stems, cut into 5- 10-cm lengths with a sterilized knife to ensure that each section has 3--4 sections. Plant a 15 cm wide and 20 cm deep planting trench on the surface of the pod, and place the stems in the trenches with a 5 cm spacing between the plants, covering a 6- to 7-cm thick fine soil. The soil is moist without watering, and when the soil is dry, it is timely watered, and the soil can be sprouted by 15-20 days. Third, field management The management of water and fertilizer timely irrigation and drainage throughout the growth period to keep the soil moist and no water accumulation. Do not need to top-dressing in the early stage, and timely topdressing urea 10 - 15 kg per 667 square meters during the prosperous period of stems and leaves. It is forbidden to water contaminated dirty water during the entire growth period, and it is forbidden to use garbage, sludge, manure (animal) excrement, nitrate nitrogen (ammonium nitrate, etc.) and nitrate nitrogen as the raw material. Fertilizer, forbid any fertilizer within 30 days before harvesting. 2. Pest and disease control Houttuynia rarely suffers from pests and diseases, and generally does not require pharmaceutical control. Fourth, timely harvesting of stems and leaves for consumption, from April to October can be harvested, can be harvested multiple times. With underground stems for products, from summer to winter can be gradually harvested according to market demand. Wash it after harvesting and tie it up. During storage and transportation, proper watering and preservation. The processing, storage and transportation process must keep the product clean and hygienic, and ensure that the requirements of GBl8406.1--2001 and the national food hygiene standards are met.