How is soil tested?

The NC Department of Agriculture and Consumer Services is a state agency that tests soils free or at a minimal cost depending on the time of year. From April to November there is no cost; from December to March the cost is $4 per soil sample. 

Cardboard sampling boxes are available at Caldwell Soil and Water Conservation District office. You fill the box ¾ full with soil and send it to the testing facility in Raleigh. Sample three to four months before fertilizer applications to ensure there is enough time to get the report back.

There are also soil test kits for sale at local garden centers. These range from $3 to $7.

Equipment Needed

  • Bucket
  • Small Garden Trowel

Be sure that all equipment is clean of dirt and fertilizer or any other debris. Equipment should be made of stainless steel or plastic. That way you avoid contaminating your sample with trace metals.


At approximately 5 to 10 locations within your property, take soil samples to a depth of 4 inches (lawn) or 8 inches (garden). Samples only need to be a spoonful or less. Each of the samples should come from the same soil type. Any soil that is very different in color or texture, should be tested separately. So avoid small areas where conditions are very different. Examples include wet spots, natural areas, landscaped areas, etc. Mix all of the samples together thoroughly in the bucket. This will give you a composite sample to test.

Testing gives you precise information regarding the condition of your soil. With that information, you are able to:

  • Save money by purchasing only the fertilizer you need
  • Ensure that you are giving your lawn enough fertilizer to thrive
  • Protect nearby ponds and creeks from excess nutrients

Request a soil test kit by emailing Caldwell Soil and Water Conservation District or call 828-758-1111, or come by the Caldwell Soil and Water Conservation District and pick one up!

Show All Answers

1. Where do I get a soil test box?
2. How is soil tested?