What Kind of Lime Should I Spread on My Grass?

Assessing Your Needs

• Although lime is a frequently used soil amendment, it is not appropriate for all lawns and should not be applied indiscriminately. Soil with an acceptable or high pH can become dangerously alkaline with the application of lime, causing nutrient deficiencies or toxicities detrimental to grass health and growth. Before applying lime, collect and submit a soil sample for a basic soil test to assess the nutrient needs and pH of your soil. Local extension offices sometimes offer soil-testing services or can recommend a soil lab.

Nutrient Needs

• All lime contains calcium, an important plant nutrient. However, some liming materials also contain magnesium. When you receive the results of your soil test, the report will indicate any nutritional deficiencies. If the report suggests applying magnesium fertilizer, you may want to consider a liming material that also contains magnesium. Dolomitic limestone or a lime that contains magnesium carbonate will raise pH and supplement the magnesium available to your lawn.

Speed of Action

• Some liming materials will change the pH of the soil faster than other limes. Burned lime, hydrated lime and pelletized limestone act quickly, while liming materials like dolomitic and ground limestone act more slowly.

Safety

• Safety often goes hand-in-hand with speed of action when choosing a liming material. Fast-acting limes like burned or hydrated lime have the potential to burn your skin as you work with them and your grass after application. If you choose these materials, you should familiarize yourself with the safety precautions on the packaging and wear gloves and other protective clothing as instructed. After applying burned or hydrated lime, water the lawn thoroughly to reduce the risk of damage to the grass.

Ease of Use

• Consider the type of spreader you have when choosing a type of lime. Fine-particle limes, like pulverized limestone, spread easier with a drop spreader. Liming materials that come as larger particles or pellets spread easiest with a rotary spreader. The lime label will indicate the fineness of the particles.

Cost

• Calcium carbonate with or without magnesium carbonate is widely available and easily obtained, making it an inexpensive choice as a liming material. It is easy to use and safe to handle. Pelletized limestone acts quickly, spreads easily and doesn't carry the same hazards as other fast-acting products, so it tends to cost the most.