Soil pH Amendment Calculator

How It Works

Soil pH affects how well plants can absorb nutrients. Most vegetables grow best in slightly acidic soil (pH 6.0-7.0). If your soil is too acidic, lime raises the pH; if it is too alkaline, sulfur lowers it. Clay soils need more amendment than sandy soils because they have more buffering capacity.

Variables

• pH 6.0-7.0 — ideal range for most vegetables, herbs, and lawn grasses
• pH 4.5-5.5 — ideal for acid-loving plants like blueberries, azaleas, and rhododendrons

Tips

• Always start with a soil test from your local extension service — they are inexpensive (often under $15) and give you an exact pH reading.
• Lime and sulfur take time to work. Apply in fall and retest the following spring for the most accurate results.
• Wood ash raises pH similarly to lime but acts faster. Use it sparingly — a little goes a long way.
• Pine needles and coffee grounds are only mildly acidic — they will not significantly lower your soil pH despite popular belief.
• If your pH is off by more than 1.5 points, make the adjustment gradually over two or more seasons rather than all at once.