How to Adjust Soil pH Naturally

Many plants require a low pH value in the soil. Azaleas and orchids need a pH of 4.0 to 5.0 parts per million (ppm), but Easter lilies and lilacs need a higher pH, between 6.0 and 7.5 ppm. Before adjusting the pH in the soil, have a soil sample tested. From where the soil sample originates will mean the difference between a factual reading and a false reading. After the results have been revealed, the soil can be naturally adjusted without using chemicals.

Things You'll Need

• Hand shovel
• Zip-lock bag
• Sphagnum peat moss
• Wood ash

Instructions

1. Shovel out a V-shaped hole about 6 inches deep. Take a wedge of the dirt and place it in a zip-lock bag. Take two or three more samples from other areas.

2. Combine all the soil in the bag. It takes a combined total of 1 pint of soil for an accurate test. Take the bag to a local university agriculture office for testing. The results will reveal the soil's pH levels.

3. Add wood ash to soil with a low pH or acidic soil. Place wood ash on the soil surface, 1 to 2 inches deep to lower the pH. Work the wood ash into the soil, reaching 6 inches deep, using a shovel.

4. Add sphagnum peat moss to soil that has a high pH or alkaline soil. Place a layer of material on the soil, 2 to 3 inches deep. Work the material into the soil 6 to 8 inches deep, using a shovel.

5. Retest the soil in three to four months to make sure the pH is at an acceptable range. Repeat the soil amendments as necessary to attain the desired results.

Tips & Warnings

• If there a large area to treat, use a garden tiller to mix the material into the soil.

References

• Iowa State University; How to Change Your Soil's pH; Eldon Everhart; April 1994
• Utah State University Cooperative Extension; Solutions to Soil Problems; Loralie Cox; December 2010
• University of Florida, Hillsborough County, Florida: Frequently Asked Questions---Soil pH & Fertilizer
• Science Education: Soil pH