If you’ve walked through a home improvement or garden store, chances are you’ve passed lime for lawns on the shelves. While the packaging often promises to “neutralize acidic soils” and “add calcium and magnesium to soil,” it’s not always clear to homeowners exactly how these products achieve this end result.

In an effort to clarify this, we wanted to walk through exactly how lime transforms your lawn.

I’ve Added Lime to My Lawn. Now What?

An easy way to think about how lime works on lawns is to compare it to how an antacid works in the stomach. Just as an antacid neutralizes excess acid in the stomach, the calcium in lime is a base that creates a chemical reaction with the soil and makes it more alkaline, or less acidic.

When soil is brought back to a neutral pH level, nutrients that once couldn’t be released to plants and absorbed (such as calcium and magnesium) are essentially “unlocked.” This ties back to the fact that neutral soil is more favorable to microbial activity. When microbes thrive in soil and break down organic matter, they mobilize nutrients and make them available to plants.

Tip: See moss or weeds in your yard, or notice that fertilizers are ineffective? These could both be signs that your lawn could benefit from a lime application. Check out this blog post for details.

Don’t Be Tempted By the Allure of “Fast-Acting” Solutions

While on the topic of messaging on lime for lawn packages, chances are you’ll see some products that advertise “fast-acting.” What seems like a quick fix can actually be troublesome.

Because fast-acting solutions tend to be more powerful than their slower counterparts, it’s more likely that a lawn will receive too much lime at once. Too much calcium can push the soil too far in the alkaline direction, and make plants unable to absorb nutrients like zinc that are necessary for healthy plant growth. This can cause plants to yellow and become weaker (and thus more susceptible to disease).

With this in mind, it’s best to choose lime products that work steadily over time. While this option may take more time to raise the pH level of soil, it is likely to produce better results — and all the while, the lime will help ward off pests that are prone to damaging lawns.

(There are plenty of other questions that surround the topic of lime for lawns. We answer some of the most common ones here.)