Soil pH

Soil pH is the measure of the acidity or alkalinity of the soil, expressed on a scale from 0 to 14. A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline.

Importance in Gardening

  • Nutrient Availability: Soil pH affects the availability of essential nutrients to plants. Most nutrients are readily available in slightly acidic to neutral soils (pH 6.0 to 7.0).
  • Microbial Activity: Beneficial soil microorganisms thrive best in neutral to slightly acidic conditions, aiding in the decomposition of organic matter and nutrient cycling.
  • Plant Growth: Different plants have specific pH preferences. For instance, blueberries prefer acidic soils (pH 4.5 to 5.5), while most vegetables grow well in slightly acidic to neutral soils.

Testing Soil pH

  • Soil Testing Kits: Available at garden centers, these kits allow gardeners to test the pH of their soil using a simple color-changing solution.
  • pH Meters: Electronic pH meters provide a more precise measurement of soil pH.

Adjusting Soil pH

  • Lowering pH (Making Soil More Acidic): Add sulfur or aluminum sulfate. Organic materials like pine needles or peat moss can also acidify soil gradually.
  • Raising pH (Making Soil More Alkaline): Add lime (calcium carbonate) or wood ash. These materials neutralize acidity and increase soil pH over time.