How can the problem of ventilation inside the pot be solved when growing Chinese orchids in the north?

Chinese orchids have a fibrous root system, and the roots are very fleshy. The roots have a high water content; according to a measurement on September 6, 2001,Cymbidium ensifoliumthe root water content was 85.6%, but their ability to absorb water and nutrients is weak and their oxygen requirement is high, so ventilation (air) is called theorchid growing"first element". If the roots lack oxygen (air) and breathing is difficult, the roots' absorption of water and nutrients is hindered, and over time the roots will suffocate and die; in addition, carbon dioxide accumulates in the soil, affecting the normal activity of aerobic bacteria and making it difficult for available nutrients to be released; it also makes anaerobic bacteria active, accumulating harmful substances such as hydrogen sulfide, which directly poison the roots, causing root poisoning and rot and leading to plant death.Orchid growingfailure often lies here. The solutions are: (1) Orchid pot: choose a clay pot with side holes and a large drainage hole at the bottom; if the diameter of the bottom drainage hole is less than 4 cm, add small holes around the original drainage hole. Replace the tile covering the drainage hole with a mineral water bottle: take the upper 5-7 cm of the bottle, use a red-hot iron tool to make many holes in it, and then use it. Using a drainage hole cover instead of a tile is even better, thereby increasing air exchange. (2) Growing medium: choose granular growing media that are both airy and water-retentive, such as volcanic stone, vermiculite, water slag and charcoal; using Kanuma soil, imperial stone or akadama is even better. They are divided by size into three types: 1.5-2.5 cm, about 1 cm, and 0.3-0.5 cm. Use large granules for the lower layer 4-7 cm, medium granules for the middle layer, and small granules for the upper layer 2-3 cm. It is not suitable for use in an especially dry environment. For a specially made clay pot with many side holes, use a mixture of two-thirds not yet fully rotted cypress leaves and one-third volcanic stone and charcoal. With this growing medium, special attention should be paid to keeping drainage unobstructed, to prevent the cypress leaves from staying wet and not drying out after absorbing enough water, which affects ventilation, causes oxygen deficiency, and leads to root rot, or even death. In addition, in summer with more rain, the leaves rot completely and the granules become smaller, weakening air permeability, so it must be replaced once a year. Comparing the two, granular growing media are more reliable. In Jinanbalconyorchid growing, choosing a mixture of multiple materials such as bark, humus soil and sand grains... is both moistening and airy, and the effect is also good. Wang Tao, Shandong Academy of Agricultural Sciences