Q.    I’ve been gardening in the same spot and amending the soil in that spot for approximately 15 years.  How can I tell what condition my soil is in?

 

Don’t guess, soil test!  Sound familiar?  The Michigan State University soil test includes testing for pH (acidity/alkalinity), lime requirement, phosphorus, potassium, calcium and magnesium.  Soil tests take the guesswork out of what you need to add to your soil. They can also help to avoid wasting money and to avoid putting chemicals into the environment unnecessarily.  Additionally, they can help to avoid wasting money on plants that are not suited for your soil.  Remember, the main purpose of a soil test is to supply people with enough information to make wise purchases of fertilizers and soil amendments.

 

To take a good soil sample from your lawn or garden you can use a small trowel, or core-sampling tool (soil probe).  Dig the samples in a zigzag fashion throughout the area from 10-15 different spots around your lawn or garden to get a good composite look at your soil.  Avoid sampling unusual areas such as those near roads, manure or compost piles or under eaves. 

 

For a lawn sample, you need to test only the top 3 inches of the soil, but don’t include the turf.  For a garden sample, be sure that the sample is representative of the garden area of interest.  Sample the soil to a depth of about 6 inches or your normal tillage depth.  Samples can be taken any time of the year.

 

Place your composite sample (consisting of 10-15 sub-samples) in a clean plastic pail or container and mix thoroughly.  Do not use a metal container as this may affect the test.  Now, spread about 3-4 cups of the soil out on a clean dry tray or piece of cardboard to dry.  Once dry, package two cups in a plastic bag or similar container.  If you have a lawn sample and a garden sample, be sure to keep them separate and labeled.

 

Bring the sample to your local extension service.  There is possibly a small fee per test sample.  The results are mailed to the county extension agent for interpretation, and then results and recommendations will be mailed to you.    Additional tests can be done for organic matter and/or micronutrients at an additional cost.  The soil lab does not test for toxins and/or contaminants.