Summary: Adding lime to a lawn to grow better grass in some areas is the first “lawn treatment” prior to applying yard or lawn fertilizer in the early spring. Treating the acid soil with garden lime helps in soil stabilization by raising the soil pH allowing nutrients to be more available to grass roots.
Question: Our neighbor told us we must put lime material on our grass to raise the pH for the lawn fertilizing to work. This is news to me!
He said there is a special type of lime for lawns… is that true? Why and when do you apply lime to the soil and how much lime for grass do you use? Karol, Columbia, Tennessee
Answer: Karol, (your neighbor may be correct) before you spread lime it is always best to have a soil pH test done. Soil testing is the only real way for you to know if your lawn or turf needs an application of lime (dolomitic limestone).
Lime Corrects Acidic Soil
So, what does lime do for grass and how to tell if your lawn needs lime?
A limestone is mainly composed of calcium carbonate. It will undergo the process of cutting, crushing, pulverizing or other chemical alteration. Those used in agriculture are called agricultural lime.
For some areas on the country, the soil/dirt may be what is called “acid soil”. The way you correct acid soil (raise the pH) is by applying or adding lime (calcium carbonate). Soils with extreme acidity (and alkaline as well) do not allow lawn grasses to grow very well. A nutrient imbalance exist and the soil can in fact be “toxic”.
The acid in the soil can limit (tie up) the availability of some nutrients, reducing the lawn’s ability to use those nutrients for growing a healthy lawn grass or turf grass. In general, where you find high rainfall, you will find highly acidic soils.
I would bet your neighbor has been in the neighborhood a long time and knows you will need to add lime to your lawn from experience alone. But I would get a soil test just to be sure about its pH for a sure fire way in providing lawn care.
When To Lime Your Lawn
And… how much lime to add to lawn and garden.
The measurement of soil acidity is defined by its pH level. The scale of pH runs from 0 to 14 with a pH of 7 as neutral. Anything above a soil pH of 7 is alkaline and below a pH of 7 is an acidic soil.
Most grass seeds will grow fine with a pH ranging from 5.5 to 7.5, and for the “ideal” grass pH, most lawns would thrive with a 6.8 to 7. The exception being centipede grass which like a soil pH more on the acid side around the 6.0 area.
Raising The pH of the Lawn
If you conduct a soil test and the soil pH comes in below 5.5 you can neutralize the pH or raise it (bringing it closer to a pH of 7) by applying lime. The best lime to use on plants is “dolomitic limestone” or dolomite lime and you should be able find this “special lawn lime” at garden centers.
What amount of lime per acre?
The application rate of lawn lime per 1,000 feet is 50 to 75 pounds. The best method for liming on a lawn is with a drop fertilizer spreader.
The lime reduces the acidity of the soil with direct contact and for this reason be careful not to put lime around the roots of acid loving plants in the landscape.