Using the slide see-through method to judge whether potting soil is dry or wet

After my humble article "The Slide See-Through Method for Judging Whether Potting Soil Is Dry or Wet" was published inOrchids2004, Issue 4, it aroused the interest of quite a few orchid enthusiasts who wanted to try it. Some called or wrote to ask me, in the slide see-through method for judging whether potting soil is dry or wet, how does one see through to the degree of dryness or wetness of the potting soil? I therefore write again about the slide see-through method for judging whether potting soil is dry or wet, striving to set out what I have observed in practice and a little of my experience, sincerely to exchange with orchid enthusiasts, and to provide beginning orchid growersgrowingwith reference and guidance. 1. The slide see-through method for judging whether potting soil is dry or wet has changed the level at which the degree of dryness or wetness of the potting soil is observed. In orchid circles, everyone knows that whencultivatingorchids, the orchid pot is generally divided into upper, middle and lower layers filled with potting media of differing specifications when potting up. The so-called upper, middle and lower layers are the bottom layer (the drainage layer), the middle layer (the nutrient medium layer) and the upper layer (the surface layer of potting soil). Therefore, orchid growersgrowinghave always relied on visual inspection and experience, looking at changes in the surface layer of the potting soil, to judge the degree of dryness or wetness of the potting soil, and then decide the time to water theorchids. Based on this handed-down experience, in my daily orchid care I often look through the slide to observe at any time the color changes of the middle-layer substrate in the potting soil, and thus learn the degree of dryness or wetness of the potting soil: if the color of the middle-layer substrate becomes lighter and whitish, it shows that the substrate is already dry; if the color of the middle-layer substrate becomes deeper and blackish, it shows that the middle-layer substrate is moist; if the color of the middle-layer substrate is neither deep nor light but moderate, it shows that the middle-layer substrate is moist but not wet. The results of the above observations are the basis for deciding whether to water the orchids. Besides visually inspecting the color changes of the substrate in the pot and learning the degree of dryness or wetness of the potting soil, I also at any time lift upward the slide inserted at the bottom of the pot. At this point the orchid pot is like a door opened, and I can freely touch with my hand and observe the dry or wet condition of the potting soil substrate, so as to grasp the correct basis for watering the orchids. Having introduced this unexpected benefit, some people will certainly ask whether, when the slide inserted at the bottom of the pot slides up and down, the substrate in the pot will scatter. On this point, orchid enthusiasts can set their minds at ease in doing it, because after the substrate in the pot has beencultivatedfor more than a month, the substrate in the pot has basically set in shape and will not scatter at all. On this, I also want to further explain the substrate Icultivatewith, for orchid enthusiasts to refer to and choose when using the slide see-through method on potting soil substrate. The substrate I use to cultivate orchidsflowersis, for the growing medium: 30% humus soil, 20% unpolluted coarse stream sand, 10% small granular weathered stone (airy sandy soil) that does not easily compact, 20% Xinghong brand orchid soil, 10% peat soil, 5% reed charcoal, 5% wood charcoal (used for the bottom layer). The orchid substrate I mix myself has the characteristics of being loose, breathable, well-draining and moisture-retaining. Long-term practice by me has proved that this mixed substrate suits the growth and development of orchidflowersand can achieve the effects of thick roots, lush leaves, strong seedlings, fragrant flowers and good color. 2. The slide see-through method for judging whether potting soil is dry or wet effectively resolves the dispute over watering with false penetration. As everyone knows, watering with false penetration is also called watering half-way. In orchid circles, there is much dispute over watering with false penetration, with differing views: some oppose watering with false penetration, saying that with false penetration the substrate is only half wet, the surface soil wet and the bottom soil dry, so the orchid roots cannot get water and easily dry up and die; others approve of watering with false penetration, saying that if thorough watering is done too frequently and too much, the potting soil substrate is moist and the roots easily rot, and the orchid plant will either die or be harmed. But my view on this is to advocate watering with false penetration. Why? I believe that false penetration, as long as it is done at the right time, in the right amount and in the right way, is beneficial and not harmful to the growth and development of the orchid plant. Based on the slide see-through method for judging whether potting soil is dry or wet, I have learned that the surface layer of the potting soil is often affected by light and wind, and moreover the water given to the orchids permeates particularly quickly to the middle and lower layers, and because the water in the surface layer of the potting soil evaporates quickly, the middle-layer substrate retains moisture better than the surface layer, so it is very easy for the surface layer of the potting soil to be already dry while the middle-layer substrate is still in a moist state. Therefore, through the slide see-through method for judging the degree of dryness or wetness of the potting soil, I have found that when the surface layer of the potting soil has been dry for 3-4 days, or even when the surface layer of the potting soil has been dry for 4-6 days, the middle-layer substrate of the potting soil is still relatively moist. If thorough watering is done at this time, it will certainly increase the humidity of the middle-layer substrate, which is extremely unfavorable to the growth and development of orchidflowers. Orchid growersall know that orchids have fleshy roots, and their physiology and growth characteristics are "fond of moistness but afraid of wetness, fond of dryness but afraid of aridity." Based on this characteristic, when the surface layer of the potting soil is already dry and the middle-layer substrate is still in a moist state, I use the spray watering method, watering with false penetration, so as to keep the surface layer of the potting soil and the middle-layer substrate moist to the appropriate degree. In this way, it is more suited to the growth of orchids. In the high-temperature seasons of midsummer and early autumn, I often spray water and let it soak slowly, keeping the potting soil substrate moist but not wet, so that the orchid plants also grow robustly with lush leaves and full vitality in the high-temperature season. But the spray watering method cannot be used by spraying at random; it must be decided by looking at the season, the weather and the growth condition of the orchid seedlings. For example, in late spring and early summer, which is exactly the period of vigorous sprouting and growth of the orchid plants, and during the winter dormancy period of the orchid plants, I generally do not use the spray watering method. In short, watering orchids must proceed from actual conditions and be applied flexibly, and must never be applied mechanically. If the surface layer of the potting soil is already dry and the middle-layer substrate still remains moist, then when watering with false penetration is called for, water with false penetration; if the surface layer of the potting soil and the middle-layer substrate are already dry, then when thorough watering is called for, water thoroughly, so as to ensure the normal growth of the orchid plant. The above are my humble views; the wise see wisdom and the benevolent see benevolence, but no matter how it is put, I believe that practice gives true knowledge. (Deng Zhongfu, Dazhu, Sichuan)