Adding Lime to Your Soil
By: Paul Schnare
Monday, September 22, 2003
Most soils in the Heartland have developed under oak hickory forests and therefore have a natural pH of about 5.5. On the other hand, most crops, lawns, and garden plants prefer soils that have a pH of 6.5. Attention to pH is extremely important. If the pH of the soil is incorrect for the crop growing on it, the crop cannot remove needed nutrients from the soil. If plants grow on soils with an incorrect pH, they can survive, but they won't thrive.
To adjust the pH of soils upward, add lime. There are several different types of lime on the market. Use an agricultural limestone either in granulated, pelleted, or powdered form.
Powdered lime releases the fastest in the soil. Unfortunately it is hard to get the powder to go through a spreader. Granulated lime is easier to spread than powdered lime, but it releases much slower because the particle size of the lime is larger.
For the best of both worlds use pelleted lime. Pelleted lime is powdered lime that is glued together into pellets with a water soluble glue. The pellet is very easy to spread with a spreader and you don't have to deal with a lot of dust. After a rain the pellets dissolve, and the lime is quickly added to the soil solution to increase soil pH. The only down side to pelleted lime is that it is more expensive than either granulated or powdered lime.
Over existing lawns apply about 50 poinds of lime per 1,000 square feet in the spring or fall. If you find that the soil pH is still not high enough continue to make an application of lime each spring and fall until the pH is at the right level.
To determine the pH of your soil, use a pH test kit that you can purchase from your local garden center, or take a sample to your local University Extension and Outreach Center. Most University Centers usually run a soil test for a nominal fee.