Detailed Guide to Low-Altitude Substitute-Material Cultivation of Gastrodia (Part Two)

After 18°C-22°C cultivation for 2-3 months, the rhizomorphs of Armillaria mellea will have spread throughout the entire corncob material, and it can then be used for Gastrodia cultivation. If there is not enough Armillaria-infected material, Armillaria can be expanded and cultivated further. This method involves adding uncolonized corncobs to corncobs that have already been colonized by Armillaria, at a ratio of 50% each, with the same operation method as above, and finally covering with soil to let the fungus grow. This method is simple and easy to carry out and does not require mother spawn. As long as it is not affected by high temperatures in the environment or by pests and diseases that cause Armillaria to degenerate or mutate, it can be used in long-term cycles.

Five, Gastrodia Cultivation Methods

For low-altitude Gastrodia cultivation, indoor or outdoor sites may be chosen, and the cultivation method is basically the same. First spread a 10 cm thick, 1 m wide layer of loose soil on the ground, place the corncob fungal material on it, and spread it flat on the soil. Each layer of corncobs should be spaced 10-12 cm apart, then place one small Gastrodia tuber to the left and right of each corncob. The distance between small Gastrodia tubers should preferably be 10 cm, and they should not be too sparse or too dense. After the Gastrodia is planted, immediately cover with 10 cm of soil, then continue sowing the second layer in the same way, and finally cover with 15 cm of soil. Then compact the soil surface and around the sides. Make each bed 1 m wide, with a walkway left in the middle; the length is unlimited and can be determined according to the site. After planting, the height is generally between 30-35 cm. The sides of the bed may be retained with bricks or left exposed. In short, it must not be too wide: first, it is convenient for management, and second, it favors ventilation for Gastrodia growth.

In addition to the above method of cultivating Gastrodia with pre-cultivated Armillaria, corncobs plus Armillaria spawn, or prepared corncob fungal material, can also be planted together with Gastrodia at the same time. However, the Gastrodia must be placed close to the fungal material. The new material serves as a bridge connecting the fungal material and also as a reserve force for Armillaria growth and Gastrodia growth. This method can provide support when nutrient supply becomes insufficient in the later stages of Gastrodia growth.

Six, Management Techniques

The management of low-altitude substitute-material Gastrodia cultivation mainly involves temperature and humidity management. After Gastrodia is planted, the suitable temperature during the growth stage is between 15°C-25°C, with the most suitable range being 18°C-22°C. If it is higher than 28°C, growth stops, and above 30°C it dies. Especially during the dog days, when the air temperature remains above 30°C for a sustained period and is accompanied by high humidity, the Gastrodia will rot, and many rotten large Gastrodia tubers will be found at harvest. Therefore, first, avoid direct sun exposure, and second, take measures to lower the temperature as much as possible, preferably keeping it between 18°C-22°C. Humidity is also very important for Gastrodia growth. Generally, the suitable soil moisture content is between 50%-60%; both too dry and too wet are unfavorable for growth. If the soil is too wet, it affects aeration and makes Gastrodia prone to rot, so the soil moisture should be kept at the same level as when planted. During management, if the surface soil is found to be dry and pale, a small amount of water may be applied; it is enough to keep the surface soil somewhat moist. Do not pour too much water into the center of the soil.

Light management is not very important. Although Gastrodia is a plant, it cannot carry out photosynthesis, and it can grow as long as conditions are not completely dark. However, strong direct sunlight or exposure causes excessively high temperatures, which is unfavorable for growth. Therefore, artificial shade sheds or shaded, cool environments under trees must be used.

Aeration issue: Gastrodia growth requires a certain amount of air. Whether indoors or outdoors, under any conditions, plastic film must not be used for tight covering. The cultivation and fungus-growing areas must not be connected into one large expanse. When the width reaches 1 m, gaps or walkways must be left to facilitate ventilation.

Seven, Harvesting and Processing Techniques

Gastrodia is cultivated once a year, and the growth cycle is one year. The harvest period of Gastrodia is also the sowing period. In the Sichuan region, harvesting is generally carried out from November to December each year. At harvest, large Gastrodia tubers are selected as commercial tubers for processing, and small Gastrodia tubers can be used as seed tubers for cultivation.

The harvesting method for Gastrodia is: dig away the surface soil, take out the Gastrodia, and sort it by size. Generally, it can be divided into two major categories: commercial tubers and seed tubers. Commercial tubers are further divided by large, medium, and small into upper, middle, and lower grades, while seed tubers are further divided by size into white-head tubers and rice tubers.

When harvesting Gastrodia, it is generally necessary to harvest, sow, and process at the same time. Timely sowing is beneficial to the survival rate and yield of Gastrodia the following year, and immediate processing is beneficial for improving the quality and color of Gastrodia.

There are many methods for processing Gastrodia. A simple and easy method is introduced here. Immediately wash the freshly dug Gastrodia with water to remove surface soil and rhizomorphs, then promptly steam it in a steamer or boil it in water. The steaming or boiling time is generally about 30 minutes, and it is best when the center of the Gastrodia is thoroughly cooked. It must not be overcooked or undercooked. After steaming or boiling, dry it immediately by baking or sun-drying. During the baking or sun-drying process, when the Gastrodia is semi-dry and semi-moist, to prevent mildew, insects, and to increase whiteness, it may be fumigated with sulfur once, and then baked or sun-dried until completely dry, then stored in a moisture-proof manner.