Photo courtesy of NatC. at Flickr.com.
Garden discussions often include advice on maintaining, lowering, or increasing the pH in one’s soil. While that’s some of the most valuable advice you can get, most of us just follow the directions and go through the motions without ever knowing what pH actually is. Well, we thought you might be interested in learning, if you don’t already know.
The term “pH” itself is scientific shorthand for “potential of hydrogen,” which, in technical jargon, means “the logarithm of the reciprocal of hydrogen ion concentration in gram atoms per liter.” If you want that in everyday English, it basically means how acidic or how alkaline your soil would be if it were dissolved in water. This can be measured on a scale of 0-14, where a pH of 7.0 is perfectly balanced. Anything less is considered acidic (with anything below about 4.0 being lethal to most plant life), while anything above 7 is considered alkaline, or basic.
The best range of soil pH for lawn and garden plants is between 6.2 and 7.2, though that can vary widely according to the plant. Most soil bacteria prefer a slightly acidic range of about 6.3-6.8, as does most other beneficial soil life. Soil pH is relatively easy to measure, using either chemical or electronic testers; the latter tend to provide extremely accurate readings within seconds, and are especially useful for testing the range of pH across your entire lawn or garden.
If you find that your soil pH is too acid, some form of agricultural or hydrated lime should be added to the soil; crushed limestone or bone meal can also help. Effective organic soil amendments that lower alkalinity include powdered sulfur, a mix of rock sulfur, peat moss, and wood chips, and good, old-fashioned pine needles.
Photo courtesy of Look At My Pretty Pictures at Flickr.com.
