Here's Everything You Need To Know About Liming Your Lawn

Gardeners will most likely need to lime their lawn at some point. Lime is a soil amendment used to increase the soil’s pH, making it less acidic. When soil pH is too low, many lawn grass species cannot make use of nutrients in the soil, including those added through fertilizer. Liming your lawn enhances nutrient availability, which promotes healthy root and leaf growth. However, not all lawns require liming. Get to know the species of grass in your lawn as well soil characteristics to determine if your lawn needs liming.

Ideal Soil pH For Different Grasses

The first step in managing your lawn is understanding the needs of different grass species. Some lawn grasses are more tolerant of low pH than others. Soil pH measures the relative acidity or alkalinity of the soil. The ideal soil pH for Bermudagrass, zoysia, and St. Augustine grasses is between 6.0 and 6.5. When soil pH falls below this range, these grasses have a difficult time accessing nutrients and will not grow well no matter how much fertilizer you apply. Centipede and tall fescue grasses, on the other hand, thrive in soils with a pH around 5.5. When soil pH falls below these ranges, lawns may need liming.

Test Your Soil

Many soils throughout the Southeast are naturally acidic and require occasional liming to neutralize excess acidity. The only accurate way to determine a soil’s pH is to conduct a soil test, ideally when the lawn is dormant, during the fall and winter for warm-season lawns. The best way to do this is to submit a soil sample through your local county Extension office. While you can purchase at home testing kits online or at garden centers, these provide limited information. When you test your soil through your state’s soil lab, you will receive expert information regarding soil health. Results will indicate if any nutrients are needed as well as how much and the type of lime to add to your soil, if necessary. These recommendations are based not only on a soil’s pH, but also the soil type. 

Signs Of Acidic Soil In Lawns

There are visual cues to look for in your lawn that suggest the soil is too acidic and it’s time to test the pH. Turfgrasses struggle to grow when soils are too acid. Look for stunted or reduced growth and yellowing of the lawn as grass becomes nutrient deficient. You may notice that lawns do not respond to fertilizer applications in the same way they had before. You may also start to see more weeds. Some weeds, like dandelions and knotweed, thrive in acidic soils and readily infest lawns when the pH drops. In moist areas, mosses also establish quickly in acidic lawns. Note that many of these signs can also indicate other problems, such as a nutrient deficiency. This is why soil testing is so important.  

Benefits Of Applying Lime To Lawns

Liming your lawn improves the health and quality of lawn grasses growing in acidic conditions. By raising soil pH, lime enhances the ability of plants to utilize nutrients in the soil. This makes any fertilizer applications you make more effective. The results are a lush, green lawn that is better able to combat weeds. A healthier lawn also resists pest pressure and is more tolerant of heat and drought. Finally, the main component of lime is calcium, an essential plant nutrient. Calcium strengthens plant tissues, making them less susceptible to disease. 

Types Of Lime For Lawns

Lime is made by grinding calcium-rich limestone into a spreadable product. Two main types are recommended for lawns: calcitic or agricultural lime made from calcium carbonate and dolomitic lime made from dolomite, which contains magnesium in addition to calcium. Both are equally effective at raising soil pH and can be used as part of an organic lawn management program. Dolomitic lime is commonly recommended for sandy soils as well as those deficient in magnesium. Lime is available in a powdered or pelletized form. Pelletized (also called granular) lime is easier to spread and less dusty. 

When To Apply Lime To Lawns

Lime takes time to change soil pH, so it is best to amend soils in fall or early winter. This provides several months during the dormant season for lime to begin to work. The effects of lime decrease over time-liming is not a onetime fix. If soil tests indicate a very low pH, you may need to test and treat soils yearly until the pH reaches the desired range. After that, test soils every three years or so to determine if additional lime applications are needed.  

How To Apply Lime To Lawns

Pelletized lime is easy to apply using a push spreader such as the type used for fertilizer applications. Spreaders help ensure even coverage across the lawn. You want the lime to contact the soil, so be sure to water it in after application. You may need to water the area multiple times to work the lime down into the soil profile.  

Precautions And Considerations

There is such a thing as too much lime. Repeat or excessive applications can raise soil pH above desired levels, which can cause nutrient deficiencies, stunted growth, and yellowing (sound familiar?). It is best to base applications on annual soil tests, as soil pH changes over time. Many factors impact soil pH, such as annual rainfall, irrigation practices, soil composition, and biological activity in the soil.

Conclusion

For many homeowners, liming your lawn is an important component of lawn health care. Soil pH and nutrient availability go hand in hand, so make soil testing part of your fertility management plan. Applying lime when needed ensures your lawn remains healthy and vibrant.