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How to Mix Lime With Soil & Potting Soil

By Naomi Judd ; Updated September 21, 2017
Soil pH is important for healthy plant growth.
tilled field image by Niki from Fotolia.com

If the soil in your area is on the acidic side, then you may want to mix in lime to sweeten your soil before planting a garden. Lime naturally balances the pH of the soil because it is alkaline instead of acidic. Soil pH for gardens should be between 6.5 and 7 and can be tested with a simple soil test kit sold at any home improvement store or outdoor garden center. Properly preparing your soil in this way can make a big difference in the successful growth of your plants.

Use the soil pH test kit to determine the pH level of your soil. If your soil is too acidic, then purchase lime to add to your soil. Doug Oster and Jessica Walliser, authors of “Grow Organic,” recommend Dolomitic limestone, which is a great source of both calcium and magnesium.

Rake through your soil with a hard-faced metal rake to break up the surface of the soil. This prepares the soil for mixing the lime powder.

Add the lime to the soil before adding composts or fertilizer. Do not dump the lime onto the soil, but rather sprinkle a layer over the top of the newly churned soil. The amount of lime needed depends on the area of soil you are altering and how much you need to raise the pH. If it was a pH of 5.5 then you wouldn’t need to add as much as if it was a 4.5, for example.

Mix in the lime with the rake so that the lime gets mixed several inches into the depth of the soil. It is usually a good idea to add lime in early spring when rain is likely to fall. If you live in an area that doesn’t receive a lot of rain, then you will need to water the soil to help the lime take effect.

A few months after adding the lime, retest the pH of the soil to make sure the change has actually taken place and that the balance is now correct.


Things You Will Need

  • Soil pH test kit
  • Lime
  • Metal rake
  • Garden gloves