Why should the pH of potting medium be tested before use?

Orchid potting medium should be neutral to slightly acidic; this isorchid growinga principle that must be followed. Becauseorchidsgrow best in neutral to slightly acidic soil. Too strong an alkalinity will affectorchidsgrowth. According to relevant materials and the practical experience of orchid growers,orchidsThe pH value of potting soil should preferably be 6.5 to 7. How do you measure the acidity and alkalinity of potting soil or newly used potting medium? The simplest method is to use pH test paper. First take one spoonful of potting soil as a soil sample, put it into a container cup, then add an appropriate amount of clean water (just slightly covering the soil sample is enough). After stirring well and letting it settle clear, drop a few drops of the clear liquid from the soil sample in the cup onto the pH test paper. After it dries slightly, you can judge the acidity and alkalinity of the potting soil according to the color change of the test paper: yellow and orange-red indicate slightly acidic; red indicates strongly acidic; yellow-green is neutral (that is, pH value 7); blue-green to blue indicates weakly alkaline; blue to purple indicates strongly alkaline. If you want to specifically measure the pH value of potting soil or potting medium to be used, you can compare it with a color chart (a color chart is included when purchasing test paper), and then its pH value can be determined. Generally, after potting soil has been used for two years, its acidity and alkalinity will change. Therefore, in order to help orchids, especially high-grade rare orchids, grow robustly, when using potting medium or after a period ofcultivationafter growing, you should test the acidity and alkalinity of those soils in which orchids are growing poorly. Based on the measured value, improve the acidity and alkalinity content of the potting soil. Some orchid enthusiasts pay great attention to the acidity and alkalinity of potting soil in orchid growth management. Some orchid enthusiasts neglect this point. When potted orchids are found to be growing poorly or withering, they mostly look for causes in fertilizer and water, ventilation and light, and pests and diseases, while neglecting the acidity and alkalinity of the potting soil. If the potting soil is measured to be too alkaline, measures should be taken to increase acidity, or even replace the whole pot with new soil of moderate acidity and alkalinity. If it is slightly alkaline, then watering several times with acidic rice-washing water (let it sit for one or two days before watering) can change the slightly alkaline condition of the potting soil. (Guangdong - Leiyu)