You may have heard one of your parents or grandparents or the gardener down the street who has the best looking flowers and lawn say, “You got to add lime to sweeten the soil!” In many cases that is true, but not for every lawn or landscape. It’s important to determine the pH of the soil before adding any amendments to the lawn. pH levels that are below a scale of 6.5 are considered acidic while pH levels that are above a scale of 7.0 are considered alkaline. Neutral pH is from a scale of 6.5 to 7.0.
When soils are tested, and show that they are in the acidic range, adding lime is the appropriate soil amendment to add. If soils are in the alkaline range, then sulfur should be added. A soil test from a university extension service or accredited soil test lab is the best way to determine the current pH level. In most cases, these labs will also provide the amount of lime or sulfur needed per 1,000 sq. ft. to adjust the pH level.
There are do-it-yourself pH test kits that come with litmus paper that will provide an approximate pH level based on a color chart. These are not very accurate and may or may not provide information on how much lime or sulfur to apply.
There are parts of the US where pH levels are usually low or usually high. Parts of the Midwest generally have more alkaline or higher pH levels, although there are places where lime may be necessary. Many parts of the Eastern US and Pacific Northwest have low pH levels. Lime can be added at any point of the year, but spring and fall are best as climate such as rain and normal freeze and thaw cycles in the fall allow it to work faster.
Benefits of Adding Lime to Your Lawn
There are several advantages including:
• Improves the quality of the soil to allow plants to grow and flourish.
• Soil nutrients become more readily available to be better utilized by the plants.
• Soil microbes and earthworms are more active at breaking down organic matter at a neutral pH level.
• Plants will be greener, stronger and will develop an improved and stronger root system.
• Lime is a great source of calcium, another nutrient that improves the growing conditions of lawns and landscapes.
Common Questions Asked About Lime Applications
Can you apply lime and grass seed at the same time?
Lime can be mixed with seed or fertilizer and applied at the same time or they can be applied separately, one after the other.
How much lime is needed on a lawn?
In most cases, 5 to 10 pounds of lime per 1,000 sq. ft. is the standard rate, unless a soil test indicates different amounts need to be applied.
Can the application burn the lawn?
Too much of a good thing is never a good idea, but rates of as high as 50 pounds per 1,000 sq. ft. can be applied without damage to the lawn if recommended by a soil test.
Is it harmful to pets?
Lime is considered relatively non-toxic to family pets. They are free to walk across a lawn that has been treated with lime. If it has been applied as a liquid instead of in a granular formulation, it would be best to keep your pets off the lawn until the spray has dried.
The important thing to understand is that one application may be good for one year, but the material will be used up by the soil microbes and will also leach through the soil profile. That is why annual applications may be required, if so indicated by a soil test.
To find out more about lime applications, contact your local lawn care professional at Spring-Green or visit our services page to learn more about this treatment.