To determine whether a lawn requires an application of lime, perform a soil test to calculate the pH balance of the soil. If the pH level of the soil is under six, add lime to amend the soil.
It is a good idea to have a state organization or a commercial soil testing lab test your soil, as do-it-yourself soil testing kits do not provide specific information on the pH level of the soil or how much lime you should add to amend the soil. If the soil test shows acidic soil, apply the recommended amount of lime using a spreader. Do not apply lime to wet, frost-covered or wilted grass.