Have you ever wondered why some lawns look more lush and healthy than others? One important factor lies below the surface of grass: your soil.

Your soil’s pH level, which indicates the level of soil’s acidity or alkalinity, can directly influence the quality of your lawn regardless of what type of seed, fertilizer or treatment you apply.

When Lime is the Solution

When your soil’s pH is below 7.0, the soil is said to be acidic.  One cause is the leaching of base nutrients such as calcium, magnesium, and potassium from the soil due to heavy rainfall or heavy irrigation. Acidic water also can be a main contributor. The good news for acidic soil is that adding lime to your lawn can repair the damage of time and depleted nutrients.

Whether you need to lime your lawn

One test can determine whether your lawn is too acidic and how much lime to apply. Do-it-yourselfers can buy a soil test kit or pH probe at your local garden center. Most soil test reports will indicate the lime requirement in pounds of pure calcium carbonate per acre, or per 1000 square feet.

When to lime your lawn

If you’re starting a new lawn, make sure to test your soil and add lime before you plant. For existing turf, spring is one of the best times to apply lime.

What exactly is lime made of and how does it work?

Lime is completely natural: made out of crushed limestone or crushed eggshells. It gives nutrients to plants and keeps a balance of other nutrients such as copper, zinc and phosphorous. It can create more porous soil which traps moisture and means less watering is needed.

It takes time for lime to work its way through your soil: up to two years to move two inches.

There are a wide variety of lime products on the market. Not all work the same way. Some have less of an environmental footprint to others depending on the amount of energy required to mine and manufacture.

Know your lime

  • Eggshell lime is made from crushed eggshells. It contains five nutrients for your lawn including calcium, potash, nitrogen, and phosphorus. One benefit is that it releases calcium quickly into soils because it’s more quickly broken down by micro-organisms.
  • Calcitic lime (also called aglime) is mined from natural, limestone bedrock deposits. The process is energy-intensive, and involves drilling, blastic, and crushing. This type of lime not only neutralizes soil acidity but also supplies calcium.
  • Dolomitic lime is mined similar to aglime. It supplies both calcium and magnesium for plant growth as well as neutralizing acidity.
  • Burned lime (calcium oxide), also called quicklime or unslaked lime, is manufactured by roasting crushed lime in a furnace to drive off carbon dioxide. It has the highest neutralizing value. But it can be difficult to handle properly because it absorbs water very quickly. When it flakes, it decomposes slowly.
  • Hydrated lime (calcium hydroxide), also called builder’s lime or slaked lime, is very caustic and not intendeded for existing turf or it will burn grass.
  • Marl is mined from deposits below peat bogs. Often, it contains impurities and has a lower neutralizing value than other types of lime.
  • Pelletized lime is finely-ground agricultural lime that comes in pellet form. During rain or irrigation, these pellets dissolve. Unlike regular liming materials, there is no dust problem associated with applying. For new lawns, apply pellets to the soil surface and water thoroughly before tilling.

Lime application tips

  • Wait for a dry spell when the ground has thawed. If you lime the soil is too wet, it is difficult to obtain an even distribution.
  • Level off your soil before applying. Lime needs to be spread evenly over the entire area because it does not move horizontally.
  • Wear gloves if you are handling calcium carbonate (also called calcic lime).
  • Use a spreader for better distribution.
  • Cover off areas you don’t want lime to be spread before you start.
  • Avoid tracking lime dust onto patios or into your house.
  • Don’t overapply: before you spread more than 75 pounds per 1,000 square feet, check with the experts.

Regardless of what type of lime you apply, it can increase your yard’s plant growth and healthy green color.