The acidity and alkalinity of plant materials should be measured.

Orchid pot planting material should be acidic, which is a principle that must be followed in orchid cultivation. Because orchids grow well in moderately acidic soils. Too much alkalinity will affect the growth of orchids. According to the relevant information and the practical experience of Lanjia, the pH value of orchid basin soil is 6.5~7.

How to determine the pH of pot soil or new plant material? The easiest method is to use pH test paper. When measuring, first take a spoonful of soil from the basin as a soil sample, put it into a container cup, and then add an appropriate amount of water (slightly soaked in the soil sample). Stir well and clarify. Drop a few drops of the clarified soil sample in the cup onto the PH test paper. A little later, the pH of the basin soil can be identified according to the color change of the test paper: yellow and orange are slightly acidic; red is strongly acidic; yellow-green is neutral (i.e. pH 7); blue-green to blue is weakly alkaline; blue to purple is strongly alkaline. To determine the pH of the soil or plant material to be used, the pH can be determined by comparing it with a color plate (the test paper is purchased with a color plate).

Generally, the pH of the basin soil used for two years will change. Therefore, in order to make orchids, especially high-grade orchids, grow healthily, the pot soil after using plant materials or after a period of cultivation should be tested for pH value of those orchids that grow poorly. According to its measured value to improve the basin soil pH content. Some orchid friends in orchid growth management, pay great attention to the pH of the basin soil. Some Lanyou ignored this point. When it is found that some potted orchids grow poorly or wither, they often look for reasons from fertilizer, ventilation and light, diseases and insect pests, while ignoring the pH of the pot soil.

If the basin soil is too alkaline, measures should be taken to increase acidity, or even the whole basin should be replaced with new soil with moderate acidity. If slightly alkaline, pour several times with acidic rice washing water (placed one or two days later), you can change the basin on the alkaline condition. (Guangdong-Thunderstorm)