Importance of pH in Growing – an Introduction and Overview

The availability of elements, nutrients, minerals, and fertilizer for plants depends on the pH of the water and fertilizer solution the plants are absorbing. pH describes the concentration of acid and base within the solution being measured. When more acidic ion species are present in solution than basic ion species, the pH of the solution will be low. As there are a large variety of acidic or basic ion species that can impact the solutions pH, it is common to describe concentration of acidic species as the concentration of free Hydrogen [H+]. This is because the molecule most abundant in the water and fertilizer solution is water, which can break up into Hydrogen and Hydroxide, and bond to different ions. It is also common to describe the concentration of basic ion species as the concentration of Hydroxide [OH-] in

When a plant is subjected to a pH that it is not well adapted to, it may not be able to absorb the elements that it needs.

As the pH changes, ions in solution will disassociate with each other, and for new bonds with other ions.  Different elements or ions are available over different pH ranges.  Different plants have different abilities to absorb elements at different pH’s.  When a plant is subjected to a pH that it is not well adapted to, it may not be able to absorb the elements that it needs in adequate quantities even if they are abundant, or it may absorb it too well, and over absorb to the point of toxicity. 

The pH scale is a logarithmic scale that is typically displayed within the range of 0-14.  IT can go beyond those bound, though these are very extreme pH levels.  The center of the scale is 7.  At this point, all the charges on acidic and basic species are neutralized, and there are no free ions floating around in solution.  It is important to remember that the scale is logarithmic, not linear, so the amount of acid to take the pH from 7 to 6 is drastically less than is needed to take the pH from 6 to 5.

We really hope this brief introduction gives you a pretty good idea of why pH matters, and how it can impact your plants.  There will be more blogs on the topic to come. 

If you have any questions or comments, feel free to reach out to

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