Granular potting media can also cause fertilizer burn, so be on your guard

I used to think that granular potting media was hydrophobic, so I could fertilize boldly and without worry. I once applied a dilute chemical fertilizer solution once a week. The first year the results were quite good, but after that things went increasingly wrong, and in the end a large number of plants withered and died. Investigating the cause of death, I first suspected some kind of orchid disease, and only in the end did I realize the culprit was the granular potting media. Although granular potting media does not hold standing water, part of the fertilizer water is absorbed by the granules during fertilization, and the drier the granules, the more they absorb. After the fertilizer water is absorbed by the granules, as the water evaporates, the fertilizer water reverts to fertilizer, which accumulates within the granules. With each fertilization, it accumulates again and again. As a result, the granular potting media almost turns into granular fertilizer, causingorchid plantsto die in large numbers. This situation mostly occurs inbalconyorchid growingand indoororchid growing, where there are few pots and a sprayer is used for watering, stopping once the granules are moist, so the remaining fertilizer in the pot cannot be eliminated. In large-scaleorchid growingthis situation rarely occurs, because the method of flushing the orchids with a large volume of water washes away the remaining fertilizer in the pot. Even so, the drawback of accumulation is hard to avoid. Therefore, the old granular media that has been replaced cannot be reused immediately; it must be soaked in clean water for a week, changing the clean water several times in between. Only old media that has undergone such purification treatment is safe. Address: Laotie, Yangyanghong, Dipu Commercial Plaza, Anji County, Zhejiang Postcode: 313300