What is the suitable dryness and humidity for orchids? A detailed explanation of humidity requirements for care

Some people say that "the wet methodfor growing orchidsis good," while others say that "the dry methodfor growing orchidsis good." Do the "wet" and "dry" requirements of these "wet method" and "dry method" refer only to air dryness and humidity, or only to soil dryness and humidity, or to dryness and humidity in both air and soil? These two ways of putting it are themselves vague and general, making the meaning feel insufficiently clear and easy to confuse.Orchidsinvolve requirements for dryness and humidity. What is meant should be two aspects: air humidity and soil humidity, andorchidshave very different requirements for dryness and humidity in these two aspects. If both aspects of dryness and humidity are generally managed with the "wet method" or the "dry method," this is very unfavorable for the growth oforchids. From the actual situation, the orchid's requirements for dryness and humidity are, on the one hand, a relatively high air humidity, while on the other hand, the soil's dryness and humidity need to be "moist but not wet," "dry but not parched," and "moderately dry and wet." Some orchid types even take "leaning toward dry" as best. How can this be seen? Let us try to discuss it from the following angles. From the characteristics and functions of the orchid's organ structure. Theorchid'sroots are one of theorchid'simportant organs. They are fleshy roots, composed of the velamen, cortex, and central column, with no fibrous roots and no root hairs. The function of orchid roots is to absorb and store water and nutrients and supply them to the leaves. It is precisely because orchid roots belong to this unique structural feature of fleshy roots that orchid roots like loose, water-permeable, and air-permeable conditions. If the potting soil is soaking wet for a long time, the respiration of the orchid roots is affected, airborne bacteria multiply greatly, and over time, poor aeration will cause the orchid roots to turn black and rot. Orchid roots are fleshy roots and have strong water retention. If the potting soil dries out completely and cannot be replenished with water in time, it causes reverse osmosis of water within the roots. Over time, the orchid roots will gradually shrink and dry out due to water loss, leading to hollow roots, and the leaves will also dehydrate due to lack of water. Theorchid'spseudobulbs are plump and short, and their function is also to store water and nutrients and to play a conducting role. The outside of the pseudobulbs has a very thick cuticle, which can effectively prevent water loss. The leaves of orchids have a very thick cuticle on the outside, with dense stomata on the underside that are slightly sunken, which can slow the rate of water transpiration and also serve for respiratory gas exchange and photosynthesis. These unique structural features of orchids show that orchids can tolerate drought and do not need excessive water, and the potting soil should not be too wet, as too much wetness easily rots the roots. However, because orchid roots have no fibrous roots and no root hairs, the area available for absorbing water is limited, while orchid leaves are also clustered, giving a relatively large area for transpiration, so a relatively high air humidity is needed to compensate. Everything needs a limit; going too far will not do, and falling too short is also not good. In my humble opinion, the dryness and humidity of orchid potting soil is still best as "moderately dry and wet, leaning dry within moisture." Leaning dry within moisture favors aeration and favors orchid growth. From the ecological environment of wild orchids. Wild orchids have neither a greenhouse to control temperature and humidity nor artificial watering and fertilizing, yet wild orchids still grow continuously and reproduce and survive. Why is this so? This is related to the fact that the natural ecological micro-environment conditions of the wild orchids' native habitat conform to the orchid's various habitual requirements, such as "liking moisture but fearing wetness," "liking dryness but fearing parching," "liking sun but fearing heat," "liking wind but fearing cold," and "liking rain but fearing flooding." Orchids grow in deep mountains and secluded valleys, either in rock crevices, or under tree shade, or on the mid-slopes of mountain streams and secluded valleys. Gentle valley winds, murmuring flowing water, and misty fog form a superior natural ecological environment with high air humidity. Orchids growing on steep mid-slopes: when rain comes, most rainwater runs off down the slope, and part of the water seeps into the soil layer, making the soil both moist and not waterlogged, with no risk of accumulated wetness. The humus in the native habitat of wild orchids is rich in nutrients, loose and air-permeable, and also has a certain moisture-retaining property, so when drought occurs, the soil will not quickly dry out completely because of the drought. These superior natural ecological environments are the inevitable result of why wild orchids can grow continuously and reproduce and survive. For homegrownorchids to grow well, the growing medium is the foundation, and water management is the key. The selection and ratio of the growing medium should take into account both looseness and air permeability as well as drainage and moisture retention. In different seasons, under different weather, and at different growth stages of the orchid plant, orchid seedlings have very different requirements for the dryness and humidity of the potting soil, and this can be addressed through different water management. Generally speaking, in spring keep the potting soil moist. In summer, temperatures are high and water evaporates quickly, so it is suitable to water more. In autumn, temperatures drop, orchid growth gradually slows, so water when it is dry and leave it alone when it is wet. In winter, temperatures are low, orchids enter dormancy, and the potting soil should be slightly dry; potting soil that is too wet easily causes freeze damage. In addition, on sunny days one should water more, and on rainy days do not water. From the fact that different types of orchids have different requirements for potting soil dryness and humidity. There are many types of orchids, and different types of orchids also have differing requirements for potting soil dryness and humidity. When cultivating orchids, the handling of potting soil dryness and humidity should vary by type and be treated separately; one cannot uniformly adopt wet-method care or dry-method care. Practice has proven that when potting soil dryness and humidity are handled properly, orchids grow well, and when handled improperly, orchid growth tends to weaken. Orchids are mesophytes. Overall, most orchid species are relatively drought-tolerant and do not need excessive water, and the potting soil should not be too wet. However, orchids differ, and their requirements for dryness and humidity also differ.Cymbidium goeringiitypes avoid dryness, like shade and moisture, and cannot tolerate heat;Cymbidium sinensetypes tolerate dryness but fear cold;Cymbidium ensifoliumtypes are rough-growing and easy to keep, tolerating both dryness and slightly wetness, with very strong adaptability;Cymbidium faberitypes are more drought-tolerant than other orchid species and are also cold-tolerant; whileCymbidium kanrantypes, especially pureCymbidium kanran, have even stricter requirements for air humidity and potting soil humidity: air humidity should be high, and the potting soil must absolutely not be too wet, with leaning dry being appropriate, because too much wetness very easily rots the roots. Practice has proven that for orchid species with relatively thick and large roots, such as the original variety ofCymbidium ensifoliumtypes,Four SeasonsOrchid, Golden-EdgedFour SeasonsOrchid, Silver Needle, and others, because the roots are plump and thick and the water stored in the roots is relatively greater, there is no need to water too frequently, and it is best to keep the potting soil leaning dry within moisture. Practice has also proven that for orchid species with thick leaf cuticles and good glossiness, such as Tiegu Su, because water evaporation is small, watering must be controlled. According to observation, the speed at which orchid roots rot due to overly wet potting soil is faster than the speed at which orchid roots shrink and dry out due to completely dry potting soil to form hollow roots. The above is a superficial view and is not necessarily correct; I earnestly hope experts will not hesitate to instruct me. Author: Zhang Bingfu, Longyan, Fujian Contact address: Shengyuan Cuo, Dongxiao Xilian, Longyan City, Fujian Province Postal code: 364012 Home phone: 0597-2790593