How to Testing and Amending Lawn Soil

What you’ll need

  • trowel
  • lime or sulphur
  • bucket
  • face mask
  • soil test kit (or access to local Extension office)
  • spreader

step 1: take soil samples

You will need to gather samples from several spots, since soil characteristics vary across your lawn. Take one random sample for each 1,000 square feet of lawn. To take a sample, dig 3 inches into the ground and scoop up a handful of soil with a trowel or use a soil probe. You should use clean tools to avoid contaminating your sample. Place your samples in a clean bucket and mix random samples thoroughly. (clean the bucket ahead of time with anitbacterial soap) Scoop out 1 cup of soil. This is your sample, ready for testing.

More info about taking soil samples:

step 2: test your soil

County extension services in many areas offer reliable soil testing or can recommend a place for you. Look for “Cooperative Extension” under the county listings. Do-it-yourself kits are also available from garden centers. You should allow up to four weeks for a soil report to arrive in the mail after you mail your sample for testing.

Your soil report will indicate soil pH, phosphorus and potassium levels, and percentage of organic matter.

More about soil testing:

step 3: interpret results

A pH rating below 7 means your soil is acidic. Acidic lawns are treated with lime to raise pH. If your soil has a low pH, consider yourself lucky — it’s much easier to raise pH than lower it. Use sulfur to lower pH if your lawn rates 8 or higher. You can buy lime and sulfur at garden centers and home centers (look in the gardening aisle).

Test results for phosphorus and potassium reveal how well these elements will nourish your new lawn. A soil test lab will offer suggestions for improvements. Many do-it-yourself kits also suggest products that increase phosphorus and potassium. If you have been following an annual feeding program for your lawn, then your lawn should have an adequate level of phosphorus.

Your soil should contain 2 to 5 percent organic matter. Sphagnum peat, compost will raise organic content.

step 4: amend your soil

Lime and sulfur are available in many forms. Finely ground limestone is safe and effective. Finer grinds work faster, but it can take several weeks for ground limestone to change pH. Hydrated lime, or quicklime, works faster, but it’s caustic, so apply it carefully. Lime pellets are safe, effective and moderately fast-acting, combining hydrated lime and ground limestone in easy-to-handle pellets.

Use granular sulfur to lower soil pH. If only powdery sulfur is available, spread it on a calm day and wear a face mask.

If your soil is low in nutrients such as phosphorus and potassium, then you should fertilize your lawn and begin an Annual Program of regular feedings.

Lawn Soil also works well to boost the percentage of organic matter. Spread 1 to 2 inches over your lawn and then water the lawn to clean the soil off the grass (see the back of the bag for recommendations on how much to add to your soil).

More about soil amendments:


Take a walk across your lawn. Do your footprints stay visible in the grass for more than a few seconds? If the answer is yes, your lawn needs water.