Definition: Soil pH is measured on a scale of zero to fourteen, with zero being very acidic and fourteen being very alkaline. Most plants grow best with a neutral pH of between six and eight. If the pH is off in either direction, plants won't grow, fruit, or bloom as they should.
Also Known As: pH soil acidity
Examples:Rhododendrons enjoy slightly acidic soil with a pH between 4.5 and 6.5.