What exactly makes an ideal three-in-one potting mix?

PlantingOrchids, how to correctly select and blend the potting mix to create good conditions for normal root growth, this is often the key to success or failure. OrchidsOrchid roots like a loose, fertile, well-aerated growing medium that is moist but not muddy - this is the experience summed up by orchid growers through the generations. Based on the experience provided by predecessors, and centering on the growth habits of orchid roots, over more than ten years I have made some attempts in selecting and blending potting mixes for growing orchids. I have successively used many kinds of materials, such as charcoal, pond mud, crushed brick, tile fragments, furnace slag, sawdust, crushed sponge and so on, and carried out various combinations, and also achieved certain results, but I feel that although the above materials each have their own characteristics, they lack organic matter, and the shortcoming of poor heat dissipation is obvious, so they are not ideal for orchid root growth. When the above materials are used as potting mix, the dryness and moisture inside the orchid pot are not easy to control. It is still acceptable for those with rich experience in growing orchids, but for beginners and those with insufficient experience, if watering and fertilizing are even slightly careless, it is very easy to cause the potting soil to become too wet, with poor aeration, thus causing orchid roots to turn black and rot, resulting in unnecessary losses. In view of the above reasons, I made a new attempt at the combination of potting mix, using lightweight refractory brick granules as the bottom layer of the orchid pot, using lightweight refractory brick granules, pond mud and dry cow dung as the filling material for orchid roots, and spreading a layer of lightweight refractory brick granules on the pot surface as a cover. Growing orchids with this blended mix has achieved excellent results. Over the past few years, I have successively used it to plantCymbidium sinense、Cymbidium ensifolium, rabbit-ear orchid, tiger-head orchid,Cymbidium goeringiiand others. On the east-facing balcony on the top floor of the fifth floor, a orchid shed was built, and with only a little shade from flowers and trees, all kinds oforchidsgrew admirably, with a relatively high rate of sprouting and flowering, robust and vigorous plants, thick green leaves, and they were not prone to disease. After a long period of comparison, I found that the three-in-one potting mix of lightweight refractory brick granules, pond mud and dry cow dung is relatively ideal, with the following advantages: ① Light in weight and low in cost. Because the structure of lightweight refractory brick granules is not very dense, their self-control of moisture is very good - even if soaked through with water, no water drips when they are scooped out, yet they themselves maintain a certain humidity. After several years of trial, when this potting mix is used in summer with the heavy watering method to manage orchids, watering three or so times a day, the moisture content of the potting mix changes little compared with moldy rainy days, aeration and ventilation are very good, and the brick granules on the pot surface very easily grow green moss, so that the humidity difference between the upper and lower parts of the potting mix in the pot is not great, which is beneficial to orchid root growth and suitable for beginners to try. ② Because the lightweight refractory brick granules themselves have large air pores and the dry cow dung is loose, the heat dissipation performance is relatively good. The pond mud and dry cow dung also cause the potting mix to maintain a certain amount of organic matter and a certain acidity, so the fertilizer retention and storage performance is good, making it easy to create a reasonable medium for normal orchid root growth, and providing favorable conditions for the reproduction of orchid root fungi. ③ It has a long service life, is not limited when growing orchids in various pots, and as long as the blend is reasonable, the potting soil will not become compacted. Under normal orchid growth conditions, as long as fertilizer is reasonably applied on time, there is not much problem even if the pot is not changed for several years. It is worth noting that the lightweight refractory brick must be used in granular form, with the size depending on the size of the pot. Years of practice by myself have proved that the effect of the "three-in-one" potting mix is good. Orchid friends everywhere, if conditions permit, might as well give it a try. Hu Yaokun