The vast majority of flowers, perennials, vegetables, and fruits grow well in a neutral soil pH between 6.2-7.0. But some species – or more precisely, some varieties of those species – require an acidic soil for optimum growth and health. What pH is considered an acidic soil? pH is the measure of how acidic or alkaline your soil is: 7 is neutral; lower numbers are more acidic, and higher numbers are more alkaline. The pH scale is logarithmic, meaning that a change in 1 pH unit is a 10X change in acidity or alkalinity. A soil pH of 6 is 10 times more acidic than a soil pH of 7; a pH of 5 is 100 times more acidic than a pH of 7. So it’s important to know the natural pH of your garden soil (the pH you can expect across your property) and if a particular plant requires …