pH is a measure of the level of acidity or alkalinity of the soil solution. Plant nutrients must dissolve or they cannot be absorbed by plant roots. At different levels of pH, the relative solubility of these nutrients changes.
At a soil pH of 6.5 to 7.0, necessary plant nutrients have the greatest solubility. This is why you may have heard that a slightly acid soil is the “optimum” pH for growing plants.
Most common garden vegetable plants prefer this soil pH range, and some garden soils can be managed to make small changes in soil pH. Other plants are known as acid-loving plants (i.e., azalea, blueberries). It’s not that they like acidic soils; it’s that they have a higher need for those nutrients that are more soluble at lower (i.e., more acid) pH levels.
Many Cooperative Extension offices offer soil testing which will give you an accurate soil pH. Take a look at this University of Florida bulletin to learn more about soil pH, how to test soil pH, and how to make changes in soil acidity, if needed: Soil pH and the Home Landscape or Garden.
