Don’t let bad soil sabotage your lawn — test it today.

Maintaining the proper pH in your soil is crucial for growing a lush and verdant lawn. If soil pH is off, essential nutrients like phosphorus nitrogen and potassium will be locked in the soil and inaccessible to your grass seeds and existing turf, resulting in thin, yellow, sickly looking grass and stagnant growth. Even worse. Soil that’s too acidic or alkaline will also promote weed growth. The best way to alter the pH of your soil is by adding lime to raise the pH (if it's acidic) or sulfur if the pH is alkaline (too high). 

Related: 3 Reasons Your Seedlings Are Flopping Over

Before Your Get Started

Don’t assume the pH in your lawn is too low or too high or you could end up doing more damage than good. Your first step should be to purchase a soil test kit and test the soil to determine its pH, so you can apply the right amendments. 

How to Raise pH

If your lawn’s pH is below 6.0, you need to add lime to it to raise it. While there are various treatments you can use to raise the soil pH, lime is the most effective and easiest to apply. Go with pelleticized limestone, which you can apply with a broadcast or drop spreader.

Pro Tip: Use dolomitic lime, which contains calcium and magnesium, thus allowing you to increase the pH while also adding nutrients that are beneficial to your lawn in a single application. 

Apply between 25-50 lbs. of lime per 1,000 square feet for moderately acidic soil with a pH below 5.5-6.0. For highly acidic lawns with a pH below 5.5, apply 50 lbs. per square feet. Don’t apply more than 50 lbs. per 1,000 square feet to avoid damaging your lawn with too much lime. Be patient with the results. It takes about 3 to 6 months for a lime treatment to show any substantial change to your soil pH. 

How to Lower pH

If your soil pH is above 7.0, it’s too alkaline and you’ll need to add sulphur to lower it. To lower soil pH add between 0.5 and 1.0 pounds of elemental sulfur per 1,000 square feet. 

As with lime, it takes about three to six months for the bacteria in the soil to change the sulfur into acid, so wait about six months before retesting the soil. If you’re looking for a faster fix, you can also apply ammonium sulfate, which will lower your soil’s pH in a few days. Be cautious when using it as ammonium sulfate can be toxic in higher concentrations. 

FAQs

When is the best time to raise or lower the pH of my lawn?

Apply lime or sulfur in the spring or fall when temperatures are mild and your lawn will recover more quickly from the treatment. Fall is the best time to apply lime or sulfur as it gives the soil the entire winter for the pH change to take effect. 

How do I test my soil pH?

You can purchase soil test kits from your local home improvement store. When taking soil samples for the test, take soils samples that are 4 to 6 inches deep from several locations throughout your yard.