The pH of soil is an indication of its alkalinity or acidity. The range of pH (which is a chemistry term for “potential hydrogen”) is from 1 to 14 with a reading of 7 showing the soil to be neutral (i.e., neither alkaline nor acid). Acid soils measure from 1 to 6 (the lower the number, the more acidic the soil), while alkalinity ranges from 8 to 14 (higher numbers indicating greater alkalinity). In general, plants and especially redworms do best in the neutral range of pH, somewhere between 6 and 8 on the pH scale.
Fortunately for worm growers there are also ways to measure soil pH of a worm bed or potential bedding. There arepH meters designed that one can place into the desired soil and obtain an accurate reading.