Lime, also known as garden lime or dolomite lime, is a common additive for lawns. Lime is typically added to lawns to raise the pH of the soil and neutralize acid. For example, raising the pH of a lawn from 5 to 6 should increase the vigor and growth of that lawn by at least 5%, along with regular watering and the addition of nitrogen fertilizer.
With how much lime can do for your lawn, is it safe to use in all cases? Will lime kill grass if you use too much of it? These are important questions to ask before you lime your yard. Below, you can find these answers and some tips on how and when lime is best used for an optimal lawn.
Will Lime Kill Grass?
No, lime will not kill grass in any reasonable concentration. Lime, as dolomite lime or any other pure and natural lime product, is also a slow-release for pH alteration. Wood ash and quick-release chemical lime products are more likely to be able to raise the pH too quickly and harm the growth rate of your lawn.
In either case, though the growth rate of the grass may slow, it will not die. When the pH of your lawn is too high, you may see that the grass appears more yellow than green. This indicates that the grass is unable to absorb nutrients properly. In this case, all you need to do is raise the acidity of the soil. This is not a crisis condition and can be taken care of over time. As the pH is adjusted, you should see the ideal green color returning in as little as 3 weeks.
What Will Lime Do to Your Lawn?
Lime will allow you to raise the pH of your lawn. An ideal pH level for most grasses is between 6 and 8. Lime should only be applied if the pH of your lawn is less than 6.5. If the pH is any higher, adding lime can easily raise the pH too much, causing the grass and many other types of plants to absorb fewer nutrients over time.
The ideal amount of lime to use is one pound of pellet or natural dolomite lime is 1 pound of lime scattered over 20 square feet of lawn. Lime particles should be no smaller than 1/16 of an inch to prevent the lime from being absorbed too quickly.
Once the lime is added, you should see the pH of your lawn gradually rise by 1 to 2 points over the course of 3 months. This is not meant to be a fast process as changing the pH of an entire yard is something that should be done with care and careful monitoring.
Once the pH of your lawn is at the ideal level, you should see grass that appears greener, thicker, and maybe less coarse. There should also be less browning on the tips of the grass after each mowing.
Will Too Much Lime Kill Grass?
Ideally, you only want to lime a yard when the pH is below the ideal range. For most grass types, this means that the lawn has a pH below 6.0. Lime added to a lawn can come in both “dust” or ground and pellet or tumbled forms. Pellet or natural forms with varying sizes, from 1/16 inch and up, are ideal as they will help adjust the pH quickly and keep it there for months or years to come.
Using the powder form of lime can cause the pH of your lawn to rise too quickly and may turn your grass yellow. When this happens, it’s important to test the pH and slowly attempt to add some acid back in. At this stage, your lawn is unlikely to die if left alone but it will look sickly for up to a year.
Related Article: What Kills Grass? A Complete List of Dangers
Is Lime Safe to Use on a New Lawn?
If you’ve done all the work of preparing a patch of land for a new lawn, the last thing you want to do is apply something that could prevent your grass seeds from germinating or prevent your sprouts from thriving.
Will Lime Kill Grass Seeds?
Will lime prevent germination of grass seed or “kill” the seeds? No, lime will not kill grass seeds. However, a soil pH that is too alkaline can reduce the germination rate for all seed types. As long as your yard’s pH is within acceptable levels for the seed you are trying to germinate, you should be good to go.
Will Lime Kill New Grass or Sprouts?
As stated above, lime can reduce the germination rate of seeds if it has been used to raise the soil pH to a level greater than 8. Sprouts can also be harmed in a similar manner as new grass needs more nutrients to thrive and is more sensitive to the negative effects of a high pH.
Adding lime to a newly seeded lawn is not recommended unless the acidity of the soil is very high. A better strategy is to prepare the soil for seeding well in advance and allow a few weeks for the lime to do its work before testing the pH again. If the optimal level has been reached, this is when you should seed your new lawn.
Will Lime Prevent Grass Recovery?
Yes, lime can prevent grass recovery if it has raised the soil pH too high. As natural lime takes time to be absorbed into the soil, the effects of this are unlikely to show up for 2 to 3 months after the lime is applied. At ideal levels and a pH of 6 to 8, lime can help improve grass recovery times.
Is Lime Harmful to My Grass Type?
Not all grass types respond to the application of lime in the same way or have the same pH needs.
Will lime kill centipede grass?
Centipede grass is a little different than most turfgrasses. Centipede grass thrives on acidic soils with a pH between 4.5 and 6. Given this, a centipede grass lawn will rarely benefit from liming.
Will lime kill St. Augustine grass?
St. Augustine grass prefers slightly acidic or neutral soil. The goal for soil pH with a St. Augustine lawn should then be somewhere in the 6 to 7 range.
Will lime kill Bermuda grass?
Bermuda grass, like St. Augustine, prefers a slightly acidic to neutral pH. This means lime should be added if the pH is less than 6.
Will lime kill Zoysia grass?
Zoysia grass is very forgiving when it comes to pH but still thrives best with a pH of around 6.5. Lime should be added to raise the pH if levels ever dip below 5.
How Do You Reduce Lime Added to a Lawn?
Getting rid of too much lime can be tricky, especially if you’ve used a powdered lime product. If too much lime has been applied to your yard and it cannot be physically scraped away or removed in another manner, you will need to neutralize it. The ideal substance to neutralize dolomite lime is sulfur.
Lime Overuse Is Easy to Correct
Lime is often beneficial and rarely dangerous when used responsibly. It can help improve nutrient uptake, recovery times, and overall color. Over-application of lime to a lawn will not kill that lawn and you should have a good window of time to correct the pH of the soil before things get dicey.
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