A pH scale is a system for testing levels of acidity and alkalinity. A soil's natural pH level is measured on a scale of 0 14.

Strawberries, for instance, flourish best in soil that is relatively acidic (ericaceous). If you care about the health of your plants, you should be mindful of your soil's pH for a variety of reasons. For example, the type and level of a soil's nutrients available for plants to absorb are directly related to the soil's pH level. A level of "0" indicates an extreme level of acidity, and a level of "14" indicates an extreme level of alkalinity.

Most plants thrive best in a soil that is neutral (pH =7).

Obviously, then, you should know your soil's pH level before you select plants for your allotment to ensure the best chances for successful growth. On the other hand, plants such as broccoli, cabbage, Brussels sprouts, and cauliflower grow best in soil that is more alkaline (or limey). Some plants, however, are exceptions. To a small degree, you can adjust your soil's pH level, but your best bet is to wisely choose the best plants.

A soil that is considered "neutral" would be a soil with a measurement of "7." Most garden soil has a pH level between pH4 and pH8.5.