Soil pH Calculator

Most garden plants thrive in slightly acidic to neutral soil with a pH of 6.0-7.0. However, some plants like blueberries prefer acidic soil (4.5-5.5), while lavender and clematis prefer slightly alkaline soil (7.0-8.0).

You can test soil pH using a home test kit, digital pH meter, or litmus strips available at garden centers. For the most accurate results, send a soil sample to your local cooperative extension service. Our calculator helps interpret any test results.

To lower soil pH, add elemental sulfur, aluminum sulfate, or organic materials like pine needles, coffee grounds, and peat moss. Sulfur is the most effective long-term option. Apply gradually over several months and retest before adding more.

To raise soil pH, add garden lime (calcium carbonate) or dolomite lime (which also adds magnesium). Wood ash can also raise pH but should be used sparingly. Apply in fall for best results and allow time for the soil to adjust.

Test your soil pH at least once a year, ideally in early spring before planting. If you are actively amending your soil, test every 3-4 months to monitor changes. Different garden areas may have different pH levels.