Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Coltsfoot Flower

Coltsfoot flower, a commonly used traditional Chinese medicine, uses its flower buds for medicinal purposes. It has the functions of relieving cough and resolving phlegm, moistening the lungs and directing qi downward, with an annual demand exceeding 1,000 tons. It is mainly produced in Henan, Gansu, Shanxi, Hebei and other provinces, with Lingtai in Gansu being the best in quality, and Guangling in Shanxi and Yuxian in Hebei having the largest planting areas.

Morphological characteristics: It is a perennial herb of the genus Tussilago in the Asteraceae family. Basal leaves with long petioles; leaf blades round-cordate, apex obtuse-acute or nearly rounded, base cordate, margin with wavy sparse serrations, upper surface dark green, smooth and hairless, underside densely covered with white downy hairs. Flowers open before leaves emerge; head inflorescence solitary, terminal, flower stems numbering from several to dozens, with downy hairs; more than ten bracts, alternate on the flower stems; involucre in 1-2 layers; marginal ligulate flowers, pistillate; central tubular flowers, staminate. Achene.

I. Site Selection and Land Preparation: It is advisable to choose semi-shaded, moist, humus-rich, slightly acidic sandy loam soil. Mountain areas, riverbanks and streamside locations can all be used for planting. During land preparation, apply 1,500 kg of compost per mu, deep plow, refine the soil, and rake it level, then make beds 1.3 m wide and 20 cm high, with drainage ditches opened around the perimeter.

II. Planting: Plant in winter or in early spring of the following year after the soil thaws, using hole planting or furrow planting on the prepared bed surface. Hole planting: dig holes at a row spacing of 25-30 cm and plant spacing of 15-20 cm, 8-10 cm deep, place 2-3 nodes of seed roots in each hole, spread them out, and cover with soil immediately after planting to level the surface; furrow planting: open furrows at a row spacing of 25 cm, 8-10 cm deep, place 1 node of the middle section of root flat every 10-15 cm (plant spacing), then immediately cover with soil and press firmly, level with the bed surface. If the weather is dry, water once after planting. About 30 kg of seed roots are needed per mu.

III. Field Management: Cultivation and Weeding: After seedlings emerge and leaves unfold in early April, carry out the first cultivation and weeding together with replanting missing seedlings. Because seedling roots grow slowly at this time, loosen the soil shallowly to avoid damaging the roots; the second time in June-July, when the seedling leaves have fully emerged and the root system is also growing and developing well, cultivation can be appropriately deeper; the third time in early September, when aboveground stems and leaves have gradually stopped growing and flower buds begin to differentiate, the field should be kept free of weeds to avoid unnecessary nutrient consumption. Topdressing: Generally no topdressing is applied in the early growth stage, so as to prevent excessive growth and susceptibility to diseases. In the late growth stage, fertilizer and water management should be strengthened. In early September, apply 1,000 kg of wood ash or compost per mu; in early October, apply another 1,200 kg of compost and 15 kg of superphosphate per mu. Apply by opening furrows or digging holes beside the plants, then cover the fertilizer with soil from the bed furrows and earth up, so as to maintain fertilizer efficiency and prevent flower buds from growing out of the ground and becoming thin and weak, which would affect the quality of coltsfoot flower. Drainage and Irrigation: Coltsfoot flower is afraid of both drought and waterlogging. In dry spring weather, irrigate promptly to protect the seedlings; in the rainy season, dredge ditches promptly to drain accumulated water to prevent flooding the young seedlings. Leaf Thinning: June-August is the full-leaf stage of coltsfoot flower. If the leaves are too luxuriant, ventilation and light transmission will be poor, affecting flower bud differentiation and inviting diseases and insect pests that damage the leaves. Therefore, overlapping, withered-yellow and disease-infected leaves should be thinned out, leaving only 3-4 central leaves per plant, so as to improve the plant's disease resistance, produce more flower buds, and increase yield. Intercropping: In field cultivation, coltsfoot flower can be intercropped with tall crops such as corn and taro, which can not only make full use of the land and increase income, but also provide shade, benefiting the growth of coltsfoot flower.

IV. Diseases, Insect Pests and Their Control: The main diseases and insect pests of coltsfoot flower include brown spot disease, sclerotinia disease and leaf blight, which should be controlled promptly. For aphids, use pirimicarb for control; for underground pests such as white grubs, use phoxim mixed with poison bait to trap and kill them.

V. Harvesting and Processing: (1) Harvesting: Around winter of the year of planting, harvest when the flower buds break through the soil but have not yet emerged, and the bracts turn purplish red. If too early, because the flower buds are still in the soil or growing close to the ground, they are not easy to find; if too late, the flower buds have already emerged and opened, and quality is reduced. When harvesting, pick the flower buds together with the pedicels from the stem base, place them in bamboo baskets, do not press heavily, and do not wash with water, otherwise the flower buds will turn black after drying, affecting the quality of the medicinal material. (2) Processing: After harvesting, spread the flower buds thinly in a ventilated and dry place to air-dry immediately. After 3-4 days, when the moisture has dried, take them out, sift away the soil, remove the pedicels completely, and continue drying until fully dry. In rainy weather, dry them with charcoal or smokeless coal over a gentle fire, with the temperature controlled at 40-50 degrees C. When drying, the flower buds should not be spread too thickly, about 5-7 cm is sufficient, and the time should not be too long; also turn them as little as possible to avoid damaging the outer bracts and affecting the quality of the medicinal material.