Key Technical Points for Summer Management of Gastrodia elata in Northern Shaanxi

Gastrodia elata prefers to grow in warm, moist sandy (or leaf-mold) soil and has relatively strict requirements for temperature and humidity. However, the area along the Great Wall in northern Shaanxi lies in the mid-temperate zone, where summers are hot and dry with little rain, which is unfavorable for the growth and development of Gastrodia elata. To achieve a good harvest of Gastrodia elata, the measures that should be taken in summer management are:

(1) Build a shed for shade. In summer, especially at noon during the hot dog days, due to direct sunlight, the ground temperature at 20 cm below the surface (already close to the Gastrodia elata layer) reaches as high as 30-37°C. To keep the ground temperature at 20-28°C, in summer a shed should be built above the Gastrodia elata boxes and pits using straw curtains and tree branches for shade.

(2) Spray water to lower the temperature. Between 12:00 noon and 14:00 in the afternoon, a certain amount of well water can be sprayed or misted, and a little black vitriol (ferrous sulfate) can also be added to adjust the pH value. This can both lower the temperature and supplement the evaporation of water in the boxes and pits, keeping the relative humidity in the Gastrodia elata area at 70%-80%.

(3) Cover with leaf mold to regulate temperature and humidity. If building a shed is inconvenient, a 5 cm layer of decomposed tree leaves and sandy soil can be placed on the surface of the Gastrodia elata boxes and pits. This can both retain and store water and provide shade.

(4) Drainage and aeration to prevent Gastrodia elata from rotting. In summer, ditches should be dug on the four sides of the Gastrodia elata beds and pits for drainage, to prevent flooding and waterlogging.

(5) Loosen the soil for aeration. Loosen the surface soil once every 2 weeks to promote the growth of Gastrodia elata.