pH (Potential of Hydrogen)

Last updated: March 22, 2019

What Does pH (Potential of Hydrogen) Mean?

pH is an abbreviation for potential of hydrogen, which measures how alkaline or acidic a substance is. pH is measured on a numeric scale ranging from 0 to 14.

Knowing the pH of the soil or other media is important, and can help the gardener better care for the plants and avoid serious mistakes with irreversible consequences. It can also provide some indication of which plant types will prosper in a particular media.

A substance's pH level is measured with a pH meter, tester, or test strip.


Maximum Yield Explains pH (Potential of Hydrogen)

A pH of 7 indicates a neutral substance. Any value below 7 indicates the substance is acidic, with 1 being the most acidic and 7 being the least. Any value above 7 indicates the substance is alkaline, with a pH of 7 being the least alkaline and 14 being the most alkaline.

Most cultivated plants have an optimal pH of around 6.5 (they grow best when the soil is neutral to slightly acidic). However, some plants such as pin oak, blueberry, and azalea demand an acidic pH of 4.5 to 5.5 to grow properly.

A soil's pH is adjustable by adding different materials to influence the pH. Generally, sulfur is used to lower the pH level while limestone is used to raise it. However, excess amounts of such materials can end up causing more harm to the soil and thus must be used appropriately. The pH should be strictly monitored to ensure the best health for the plants being grown.


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