Soil pH measures how acidic or alkaline the root zone is. The scale runs from 0 to 14, with 7 considered neutral. Most garden plants grow best within a moderately acidic to neutral range, but the ideal pH varies by species.
Knowing your soil pH helps explain nutrient problems that fertilizer alone may not solve. A soil test is the best starting point before adding lime, sulfur, or other amendments.
Why Soil pH Matters
Soil pH affects how available nutrients are to plant roots. University of Minnesota Extension’s soil testing guidance explains why laboratory testing is more reliable than guessing from plant symptoms or home remedies.
Acidic and Alkaline Soils
Soils below pH 7 are acidic and soils above pH 7 are alkaline. Because the pH scale is logarithmic, a one-point change represents a tenfold change in hydrogen-ion activity.
Do Not Adjust pH Without Testing
Lime can raise soil pH, while elemental sulfur can lower it over time. The correct rate depends on the existing pH, soil texture, buffering capacity, and target crop. Our fertilizer myths guide explains why nutrient management works best when it is based on measured needs.
Containers Make Special pH Needs Easier
Plants with very different pH preferences can be easier to manage in containers where the growing medium is separate from native soil. Our outdoor container guide covers drainage, pot size, and other factors that matter alongside pH.
Watch Plant Response, Not Myths
Do not taste soil or rely on folklore to judge acidity. Use a soil test, then choose plants suited to the site or make measured adjustments only when necessary. Our organic gardening guide covers soil structure, compost, mulch, and other fundamentals that work together with pH.