A professional soil test will provide you with a wealth of information about your soil, including the pH and amount of different nutrients. Your local Cooperative Extension Service office may offer a professional soil testing service. The advantage is low cost and results that are specifically geared to your location. If this service is not available, you can also have your soil tested by an independent soil lab. If possible, choose one in your own region of the country.

Soil test results usually rate the levels of soil pH, phosphorus, potassium, magnesium, calcium, and sometimes nitrogen. (Most labs do not test for nitrogen because it is so unstable in the soil.) Some labs also offer tests for micronutrients such as boron, zinc, and manganese. Unless you feel there may be a deficiency problem, you probably won’t need micronutrient testing. As a preventative measure, you can apply organic fertilizers that include micronutrients (such as greensand and kelp meal).

To get the most accurate test results, take a soil sample from each garden area: lawn, flower garden, and vegetable garden. Spring and fall are the best times to perform a soil test. The soil is more stable, and these are good times to incorporate any recommended fertilizers. Many labs will give recommendations for specific organic amendments upon request. If not, you will have to compare labels to find organic substitutes for the chemical fertilizers that may be suggested.

Soil Testing Labs
Woods End Soil Labs
RFD 1, Box 4050
Old Rome Road
Mt. Vernon, ME 04352
207-293-2457

A & L Agricultural Labs
7621 White Pine Road
Richmond, VA 23237
804-743-9401

Green Gems
P.O. Box 6007
Healdsburg, CA 95448
707-431-1691

An excerpt from the article, “Building Healthy Soil“, by Kathy LaLiberte, courtesy of Gardener’s Supply Company.