The relationship between ventilation inside the orchid pot and the activity of orchid roots

The coarseness of the potting material and the planting technique are also closely related to how well the pot is ventilated and how quickly it drains. When planting, I judge by how much space the root mass occupies in the pot, and within the range that does not scrape the root tips, I use the largest chunks of material possible, discarding anything smaller than a soybean; this prevents small pieces from clogging the gaps in the pot and turning it into an overly compact state. Apart from shredded sphagnum moss and tree-fern fiber, every piece of the other various materials comes in round, square, oval, rectangular, concave-convex, or other odd shapes. During planting, care must be taken to make the rectangular or oval pieces placed in the pot stand upright, and they must not be allowed to lie flat. The concave side of a concave piece must not face upward. This is because material lying flat will make drainage in the pot difficult. When the concave side faces up, its hollow forms a low pocket where water collects and is hard to dry; when new roots encounter such a water-collecting low pocket, the root tips are easily soaked and rot. For a pot that has been planted, it is enough that the orchid plant can stand steady; the material packed into the pot must never be too tight. We must never forget: the roots of the orchid breathe ceaselessly day and night, and gaps formed in the pot make drainage and ventilation easy, allowing the orchid roots to exert their most effective respiratory function for the longest possible time.... The active respiration of orchid roots truly gives tremendous help to the growth and reproduction of orchids. What a pity! These most crucial details seem to have been overlooked by some growers. (Wu Anlu)