A variety of tree leaves increase the acid level in soil when they break down.

How to Neutralize Tannic Acid in Soil for an Organic Garden

by Keith Dooley

Starting an organic garden with your child is not only an educational experience, but also a bonding moment, giving you a chance to spend precious time together while he's still young. As a team, you get to enjoy doing everything from tilling the ground to watering the plants as they grow; however, the task of neutralizing the soil is a chore you should save for yourself. Eliminating the affects of tannic acid requires the use of chemicals that irritate the skin and eyes, and are harmful if breathed into the lungs. It's best your little guy skip this step until he is older.

Test the soil with a pH test kit to determine how acidic it is. This is best done in the fall, so that you can adjust the soil before spring planting. Scoop up small amounts of soil 3 inches below the surface, following the kit directions, and place in the test tubes that come with the kit. Add the included testing powder and water as instructed. Determine the level of pH by reading the results and comparing them to the guide. If you prefer, have your local cooperative extension service test the soil for you. Your goal is a pH level around 7, which is neutral.

Add lime to the soil in late fall or winter. It will take at least two months for the lime to work in the soil to neutralize the acid. Measure the garden area to determine the square feet. Multiply the length and the width of the garden. Divide the number by 1,000. Multiply the results by the number of pounds suggested on the lime package for a 1,000-square-foot space. This will give you the pounds of lime needed for your garden.

Fill half of the lime into a garden spreader and walk across the garden in rows. Repeat the process with the other half, walking in perpendicular rows to the first row.

Water the ground for 10 to 15 minutes to soak the lime into the soil. Repeat the testing process every two years to check the acid levels and adjust.

Items you will need

  • pH test kit
  • Dolomitic lime
  • Garden spreader
  • Gloves
  • Long-sleeve shirt and pants
  • Mask


  • Use lime pellets for easier application. Pulverized and granular lime also may be applied; however, you must check the package for instructions on application quantities, since different types of lime vary.


  • Wear gloves, a long-sleeve shirt and long pants to prevent skin contact with the lime, which can irritate the skin. Wear a mask if you use pulverized or granular lime, since these have a finer texture and create more dust in the air.

About the Author

Keith Dooley has done work in the field of landscaping and design for more than 10 years. He has implemented his own designs, as well as pulled from techniques learned through studies, creating many landscapes for others to enjoy.He has also maintained lawns, athletic fields, town parks, large gardens and game fields.

Photo Credits

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