How to choose orchid potting medium? Adapting to local conditions is key

Growing orchidsmust be adapted to local conditions, and the materials used must not be changed at will. If one does not pay attention to the differences in eachorchid-growingenvironment and changes theorchid-growingpotting medium at will, it will inevitably bring serious consequences. I myself had a profound lesson because of this. One day in the autumn of 1999, I went to a local orchid friend's home to admire his orchids. As soon as I entered his door, I found that in the yard, over a hundred pots ofCymbidium goeringiiand Cymbidium faberi plants were robust, emerald green and tender, with not a single scorched leaf tip or black spot on the leaves, truly delightful. Envious, I could not help asking the owner for his secret. The orchid friend hurriedly "peddled" his "words of experience" to me, and pointing to a pile under the tree in front of the door, said: "I used this kind of potting medium to pot them." Looking carefully, I found that this pile of potting medium was made by mixing and composting soil, furnace ash slag, sawdust and dawn redwood leaves, with fine particles and ample fertility. A few days later I brought a cart and hauled back several woven bags of it, repotted and changed the soil, using entirely this kind of potting medium. In the spring of 2000, when it warmed and flowers bloomed, new shoots broke through the soil one after another, and by the plum rain season, some new seedlings had already grown into mature plants. Who would have thought that the wind and clouds would suddenly change: as the plum rain season ended and the intense heat arrived,Cymbidium goeringiinew seedling leaves began to show speckled black spots, which then spread to some old leaves as well, and even some Cymbidiumfaberileaves also developed black spots. Faced with this situation, though I thought of every idea and used every method, it was to no avail, and I could only resort to the use of scissors. To prevent the disease from worsening further, I strengthened water control in autumn, which in turn caused root tips to shrivel and leaf tips to dry up,Cymbidium goeringiiflower buds all withered and died, and of several dozen pots of Cymbidium goeringii, only one bloomed. I carefully analyzed this matter and believed the main reason was that I had not considered the differences in each orchid-growing environment and had used the potting medium indiscriminately. The orchid friend lived in a single-story house at the urban-rural fringe,orchidswere grown in a large courtyard of more than 50 sq m, with large cherry trees and persimmon trees planted along the south and west sides of the courtyard, whose branches and leaves could cover more than half of the courtyard. Under the trees was bare earth ground. In the middle of the courtyard were built a fairly deep groundwater pool and broad water channels, partly covered with cement precast slabs. The north and east parts of the courtyard were cement ground. This orchid friend placedorchidsmostly under the trees and beside the water, with tree leaves shading above and pool water cooling below; by day there was no smoke or dust pollution, and by night there was dew to moisten them. The orchid friend often filled the pool and channels full, letting the water overflow so the orchid pots could absorb water naturally, so in spring and summer he hardly needed to water at all, and the environmental conditions were very ideal. By contrast, my orchid-growing environment was far harsher. My home was on the east second floor within the city,orchidswere grown on a platform connecting the first-floor residents' self-built house with my south balcony, with an area of less than 20 sq m. In the plum rain season there was little wind and it was damp, in summer it was hot and stifling, and in autumn the wind was strong and it was dry. Also, because it was located in an old residential area with poor community management, the downstairs area all around was full of open-air food stalls, and air pollution was severe. Around the platform there was only a 1 m high wall; in summer I used shade netting for shade, and in autumn there was no windbreak facility. Previously I used homemade potting medium to grow orchids, made from vegetable garden soil (humus soil) plus furnace ash slag and a little river sand. Although the environment was somewhat poor, I made up for it with careful maintenance, and it could still send up shoots every year and bloom continuously, with fairly good results. This time, after using the orchid friend's potting medium, the medium was too fine and too rich; in the plum rain season and summer with high humidity and high temperature, plus being placed in the open, exposed to rain from time to time and constantly steamed by ground heat, the roots were uncomfortable, which inevitably showed on the leaves. This was the first mistake. In autumn, with frequent continuous autumn rain, afraid of a recurrence of the old disease, I strengthened water control, and as a result controlled water excessively; once struck by dry wind, the root tips shriveled, inevitably causing leaf tips to wither and blacken and flower buds to be damaged. This was another mistake, called adding mistake to mistake. Looking at so many pots of orchids cut back to half stalks, truly the past is too painful to recall, and the lesson is profound. Fortunately, I found where the crux lay, promptly changed the potting medium, and renovated the orchid-growing platform, adding shade and windbreak facilities. I believe my Cymbidium goeringii and Cymbidium faberi will surely grow luxuriantly and bloom fragrantly in the future! (Anhui / Zhu Nanfang)