The Amazing Things Lime Can Do For Your Grass

Updated: Sep. 08, 2022

If you think you've tried everything to make your lawn beautiful and it's still sparse and dull, it's possible it just needs lime.

You water, fertilize and do all the right things, but your lawn doesn’t respond to your nurturing. There may be a simple solution to your problem — lime.

What Is Lime?

Lime is an inert mineral made up of calcium and sometimes magnesium, two critical nutrients important for healthy turf growth. It is mined from the ground as limestone and then processed into a form that is easy to apply as a soil amendment. Sometimes lime comes in powder form, which is messy to handle. Pelletized lime looks more like a fertilizer and is much easier to handle and apply to your lawn with a conventional broadcast spreader.

Lime has little or no odor and is relatively safe to use when you follow the precautions on the label. Sometimes lime can be dusty and irritating to bare skin, so it’s recommended that you wear gloves, safety glasses and a mask when working with it. You also should water lime into your lawn before sending kids or pets out to play. One-quarter to one-half inch of rain or water from your sprinkler will do the trick.

Besides providing your lawn with two critical nutrients, it also raises the pH of your soil. A soil’s pH is a measure of the acidity or alkalinity of the soil. A soil with a pH of less than 7.0 is considered acidic. More than 7.0 is considered alkaline. When the pH is higher than the preferred range of 6.0 to 7.0, your soil can tie up nutrients so your grass roots can’t absorb them. This may explain why your lawn appears off-color or patchy even after you’ve fertilized.

Is Lime Good For Grass?

Not all lawns need lime. Applying lime when your lawn doesn’t need it is a waste of money and a couple hours of your precious time. You won’t know if your lawn needs lime unless you conduct a soil test. Whether you test it yourself or have a garden center or lawn care extension service do it for you, the results will reveal your soil’s pH. If your soil pH is below 6.0, you may benefit from an application of lime. The goal of applying lime is to raise that soil pH into the 6.0 to 7.0 range.

Keeping your lawn’s pH within the optimum range will ensure it can store and release all the nutrients that you feed it. It also promotes active microbial activity in the soil. Healthy soil is teeming with invisible beneficial fungi and bacteria that help break down thatch, organic matter and fertilizer so your grass can more efficiently use them all as food sources. A good soil pH encourages microbial growth and turbo-charges your soil.

What Are the Signs That I Need Lime?

Signs that your grass is not thriving and may need lime are:

  • After you fertilize, you don’t see the color response that you should;
  • You see weeds that prefer acidic soil, such as plantain, knotweed and sheep sorrel;
  • Moss is growing in your grass.

When and How Do I Apply Lime?

Throughout the U.S. and Canada, the best time to apply lime is in the spring or fall. In northern locations, applying lime in October or November before the ground freezes will allow rain to work it into the soil. The snow melt and freeze/thaw cycle during the spring will also help work it into the ground.

Your soil test will likely make a recommendation on how much lime to apply based on your pH value. Soils that are slightly acid could require 25 to 50 lbs. per 1,000 sq. ft. annually. You can split this up into two applications if you prefer, one in the spring and another in the fall.

Lime can be messy to apply if you buy the cheap stuff. Pay a little more for pelletized dolomitic lime. It will be easier to apply with your broadcast spreader, and will add calcium and magnesium to your lawn while raising your soil’s pH.