To Lime or Not to Lime? That’s the Question

No matter how hard you work on your lawn—whether you’re brand-new to lawn care or a long-time veteran—sometimes things are just … off. When attempting to improve the quality of your grass, you might consider turning to lime. Here’s everything you need to know about lime for lawns and whether it’s the right organic fertilizer you need for your specific situation. 

What is Lime for Lawns?

Lime for lawns is a natural, mineral, organic fertilizer that supplies nutrients to the grass, improving the grass’s growth. It is used as a mineral amendment for soil to increase soil pH. 

What Types of Lime for Lawns Are There?

There are two types of lime for lawns: dolomitic lime and calcitic (or agricultural) lime. Among the major differences between the two types, dolomitic lime contains both calcium and magnesium, while agricultural lime only contains calcium.

Both types of lime are known to raise soil pH safely and effectively. However, because dolomitic lime slowly releases the essential nutrients calcium and magnesium into the soil, we recommend using dolomitic lime as one organic fertilizer in your arsenal when crafting your landscape lawn care plan.

How Do I Know if My Lawn Needs Dolomitic Lime?

To know whether your lawn needs dolomitic lime to rejuvenate your soil’s low pH and grass, your first step is to perform a complete soil test to learn more about your lawn’s specific needs, including its pH levels. Thankfully, Rocky Mountain BioAg® also offers a soil test interpretation to ensure you accurately understand the results before you apply the lime organic fertilizer to boost your soil’s pH levels.

Why is Your Lawn’s Soil pH So Important?

Your soil’s pH is the secret to your lawn’s success. But what is it, and why is it so important? 

Soil pH is the measure of the soil’s acidity (indicated by having a pH under 7.0) or alkalinity (indicated by having a pH over 7.0), with a pH of 7.0 being neutral. Think of it as the balancing act—the pH indicates how well a plant will obtain nutrients from and grow in that soil. 

What is the Ideal Soil pH for Grass?

The ideal pH for North American grasses depends on the type of grass grown in your lawn. Some grasses (like tall fescue or centipede) tolerate a lower pH of around 5.5. Other grasses, like St. Augustine, Bermuda, or zoysia, prefer a pH between 6.0 and 6.5. When a grass’s pH falls well below its ideal pH, your lawn needs an organic fertilizer like dolomitic lime to raise it back up to slightly acidic levels.

When a soil’s pH level falls too low, several necessary nutrients suddenly aren’t as available to the grass. They include:

• Nitrogen
• Phosphorous
• Potassium
• Calcium
• Magnesium
• Sulfur
• Molybdenum

Signs of Acidic Soil in Your Lawn

As you’re learning everything you need to know about lime for lawns, you’ve got to know what the signs of acidity look like before you reach for the dolomitic lime.

You should be looking for things like:

• Grass color—the lawn takes on a light yellow or pale green color, either all over or in patches
• Grass growth—the grass leaves grow slowly or are stunted
• Weeds—there is an increase in weed growth, especially of dandelions and knotweed
• Moss—there is a buildup of moss, especially in moist areas 
• Lack of response to organic fertilizers—the grass may stop responding to other organic fertilizer treatments as it did in the past 

You should note that many of these signs are also symptoms of other issues, like nutrient deficiencies. This is why conducting a soil test at home is the crucial first step to your lawn’s future health.

How Should Lime for Lawns Be Applied?

Once you determine that you need lime for your lawn, you’ve got to know how to apply it properly for the best results. Our dolomitic lime is pelletized, making it perfect for easy absorption into the soil. Depending on the size of your lawn, you will likely want a spreader, just like those used to apply organic fertilizer, to help evenly spread the lime around your yard.

Just like when applying other dry organic fertilizers, dolomitic lime needs water immediately after it’s added to your grass. You may need to water multiple times to ensure the lime is immersed well into the soil.

When Should Lime for Lawns Be Applied?

Lime can take a bit of time to be absorbed into the soil, so don’t expect instant results. Because of this, you should add lime for your lawn in the fall or early winter before the ground freezes. This will provide the lime time to work into the soil while the grass is dormant. 

Liming your lawn is not typically a one-time endeavor, especially if your soil’s pH is very low. You may have to test your soil and apply lime for your lawn annually until you reach a consistent pH level where your lawn will thrive. After you’ve reached that dependable threshold, it’s good to re-test your soil every two to three years and reapply the lime if needed. 

Can You Apply Dolomitic Lime and Other Organic Fertilizers at the Same Time?

The opinions are mixed on whether you should apply dolomitic lime at the same time you’re applying another organic fertilizer to your lawn. On one hand, some think that applying lime for lawns and organic fertilizer in tandem won’t hurt, because the lime kicks in much more slowly than a lawn fertilizer does.

However, many others believe it’s best to apply the overall organic fertilizer your yard needs (like the Perfect Blend Organic 4-4-4 Fertilizer, which is balanced in nitrogen, phosphorous, and potassium) before you apply dolomitic lime to boost your soil’s pH. As alkalinity is raised, the soil’s nitrogen levels can be depleted—causing other growth issues for your lawn. To be safe, wait for a good rain shower or after soaking the organic fertilizer in your grass with water before applying lime for your lawn. 

Is It Possible to Apply Too Much Lime for Lawns?

In short, yes, it’s very possible to apply too much dolomitic lime to your lawn. As you’re attempting to raise your lawn’s pH levels to slightly acidic, you can go too far and make your soil alkaline instead. Adding too much lime for lawns can cause your grass to look yellow and stunted—eerily similar to where you may have started when your soil was acidic. 

When considering whether to apply lime for lawns, just remember: Your soil’s nutrition is vitally important. Doing a soil test, ideally on an annual basis, will help you make an informed decision as to whether dolomitic lime is the right approach for your lawn.