When to lime a lawn is an important consideration for the year to year care of fescue turf. Whether it’s calcitic lime, dolomitic lime, or even fast acting lime, knowing when and how to lime your lawn is a key part of keeping it healthy and Picture Perfect. For the most part, the most popular time of the year to apply lime to a lawn is in the fall. There are three main reasons that this is a good time to decide when to lime a lawn. However, the biggest reason is the benefits of applying lime after aeration, specifically core aeration.

Traditionally, most homeowners still prefer core aeration to newer methods such as liquid aeration, even though studies show that for the purpose of aerating soil, certain liquid products are equally or more effective. That being said, core aeration still has ancillary benefits that can be appealing based on your overall goals for this major fall service. Because both calcitic lime and dolomitic lime are notoriously slow to disperse into the soil system, core aeration can provide a bit of a head start.

On average, most lime products take several years to fully react with and disperse into the soil system. The effect that lime has on the soil starts to occur within about six months (less time with fast acting lime). No matter how you look at it, lime is one of the slowest moving components to a fertilizer program. When applied to the soil surface of a lawn, lime breaks down uniformly, slowly working to deeper levels of the soil one millimeter at a time. When core aeration opens holes in the soil several inches deep, applying lime after aeration allows some of the product to fall into these holes and begin reacting at a lower depth more quickly.

Lime is a fundamental part of a fertilizer program because of the elements it is able to introduce to the soil system, specifically calcium and magnesium. Calcitic lime is primarily composed of calcium carbonate, while dolomitic lime also contains magnesium carbonate and therefore a higher amount of magnesium. Calcium and magnesium are both key nutrients for a healthy soil system and need to be in balance with one another. Additionally, both types of lime are very basic in pH, meaning that they are perfect for neutralizing acidic soil.

Most homeowners and companies choose to perform a soil analysis on their yard at the beginning of the year when the soil is most at rest. When results show a pH below the ideal range,  more aggressive applications of lime are ideal to improve the soil acidity more quickly. This is another reason why fall is chosen for when to lime a lawn, since it is about halfway through the calendar from when the soil is tested, a timing that works well with the breakdown period we discussed earlier.

The third reason that timing is an important part of how to lime a lawn is the aftercare given to a property after fall aeration. For fescue turf, seed is applied in the fall as well, which makes aeration, seeding, and lime a typical three part service. After seed is applied, the best practice is to water it for short durations multiple times a day. This constant watering is great for the breakdown of lime as well because it speeds up the product being dissolved as well as its uniform entry into the soil system.

Even though lime is slow acting, the value it has for your soil system and lawn is well worth the wait. Lime is just one part of a well rounded fertilizer program, but its impact on soil pH influences the efficacy of every other fertilizer component you apply to your lawn. To discuss lime applications with a fall aeration and seeding service, be sure to contact your turf management representative today.