How to Take an Accurate Soil Sample

Obtain a soil sample bag or bags from a Department of Agriculture extension office. (Listed under US Government in the phone book.) It will contain directions and labeling instructions. Alternatively, purchase the bag from a commercial testing lab. The cost for either should be around $5.00 to $10.00.

Get a shovel, a plastic bucket or container, and a garden trowel. Be sure each is clean of any contaminating chemicals or dirt.

Pick a typical spot six by six inches, remove any plants, scrape mulch and leaf litter from the soil surface. Dig out a shovel full of dirt about 6 to 8 inches (15.2 to 20.3 cm) deep, and set this shovelful aside.

Use the trowel to scrape down one side of the hole digging out a half inch vertical section of soil, and place it in the bucket.

Repeat steps 2 and 3 at least three times in different parts of the garden so that the soil sample represents your whole garden when mixed. If the plot is more than one quarter acre, you may want to divide it into sections and test each section separately. This is also necessary if different sections of the garden have different soil types. For example, if part is on an alluvial flood plain and part is on a slope.

Remove anything that is not soil such as roots, worms, rocks. Then mix the soil together thoroughly.

Fill the soil sample bag or container with the necessary amount of mixed soil, complete the paperwork, and mail it to the lab.