Soil pH Basics
The pH of your garden soil refers to how alkaline or acidic it is, and is measured on a scale between 0 (acidic) and 14 (alkaline), with 7 being neutral. Generally, most garden plants like a pH between 6 – 7.5. If you live in an area that receives heavy rainfall, the soil is likely to be more acidic (lower pH), while places with less rainfall are more likely to have soil that is on the alkaline (higher pH) side. A soil pH below 4.6 or above 8.3 tends to be too extreme for most plants.
To find out the acidity of your soil, you will need to test it. You can do this on your own with a purchased kit, or you can have it tested elsewhere like your county extension office. Once you have the results, you will have an idea of what you will need to change to improve your soil for the types of plants you will be growing. This may include adding lime to increase the pH, or sulphur to help lower it.