How to Grow Gastrodia? A Detailed Guide to Mulching Cultivation Methods

For more than ten years, the author has studied, investigated, experimented with, summarized and promoted Gastrodia mulching cultivation techniques in Gastrodia-producing areas across more than ten provinces and cities nationwide, which can increase Gastrodia yield by 20-30%. The principles and technical methods of yield increase through mulching are introduced below:

Principles of yield increase through mulching. Gastrodia is a plant that prefers cool and humid conditions. In nature, it is mainly distributed under forest canopies or in shrublands, mostly growing on gentle slopes at 10-30°C. During its growth period, it likes moisture but fears waterlogging; it likes warmth, with the most suitable temperature being 20-25°C, but fears high temperatures, and growth stops when the temperature exceeds 28°C. However, for convenience and management, artificially cultivated Gastrodia is often not grown in forests. To avoid exposure to intense sunlight or heavy rain at the Gastrodia cultivation site, fallen leaves or grass are spread over the Gastrodia cultivation area. On one hand, this retains moisture and prevents drought; on the other hand, it blocks sunlight and prevents high temperatures. In addition, the mulch can also suppress or block weed growth, achieving a water-retention effect.

(1) Mulching materials. First, leaf types: fallen leaves of broadleaf trees are best, but leaves of pine, cypress, camphor and others can also be used. Second, grass types: thatch grass is best, but rice straw, corn stalks and others can also be used.

(2) Mulching thickness. The thickness is 2-5 cm. At altitudes above 1000 m it can be thinner, and below 1000 m it can be thicker.

(3) Mulching methods. Mulching is further divided into full mulching and partial mulching. Full mulching means covering both the Gastrodia cultivation boxes and the trenches, while partial mulching means covering only the Gastrodia cultivation boxes without covering the trenches. Mulching is also divided into direct mulching, which means placing the mulch directly on the Gastrodia cultivation boxes. Indirect mulching means building a shade shed at the Gastrodia cultivation site, or combining the two, that is, using direct mulching combined with indirect mulching. This method shows very obvious results when applied at altitudes of around 500 m. Where conditions permit, mulching can be done while planting. When Gastrodia enters its vigorous growth season, especially during the three months of July, August and September, attention should be paid to mulching. It must be specially pointed out that drainage ditches must be opened well before mulching.

(4) Management after mulching. If Gastrodia is cultivated in November, after trenches are opened and mulching is completed, basically no management is needed until mid-May of the following year. However, between mid-May and the end of September, regular inspections should be carried out and management should be conducted according to actual conditions. For fully mulched cultivation sites, the main task is to check dryness and humidity. For partially mulched cultivation sites, first check dryness and humidity, and second, regularly remove weeds between the trenches.

(5) Mulching with plastic film. In some places, during sexual reproduction, plastic film is used to cover Gastrodia seeds during the germination period to preserve warmth and moisture, with relatively good results. However, in the process of asexual cultivation, if plastic film is also used as mulch, great attention must be paid to the timing and method of plastic film mulching. If the mulching method is improper, it will create four environments unfavorable to Gastrodia growth: first, increased temperature; second, excessive water accumulation; third, insufficient water because the film is left on for too long without being removed and rainwater cannot penetrate; fourth, poor aeration, while excessively high temperature and humidity lead to rotting of Gastrodia. Therefore, when the temperature reaches above 20°C, plastic film should no longer be used as mulch. If plastic film is used as mulch, an appropriate thickness of soil or fallen leaves should be spread over the film according to the situation.