Why should I get an MSU Soil Test?

Why you should test your garden’s soil and what you’ll learn when using MSU Extension’s handy soil test kit.

MSU's soil test kit comes with return envelope and postage.

MSU's soil test kit comes with return envelope and postage.

Smart gardeners often think of getting their soil tested in preparation for planting in the spring because it can give seeds or plants a better chance of growing. But there are gardeners who have not heard about soil testing or are not sure what kind of information a soil test will give them.

It could be about the World View or the “Me” View.

World View: By knowing what nutrients are already in the soil, you are not adding additional, which can run off from the site. Fertilizer washing off into drains, ditches or other areas can contaminate surface and groundwater. Phosphorus causes abundant plant growth in ponds and lakes. The verdant green surface of the water is caused by algae and duckweed which are enabled by excess nutrients. Gardeners with a soil test recommendation aren’t guessing; they are using science for an answer.

“Me” View: If I know what’s in my soil, I just have to add what will help my plants grow better. I know what to use and how much to apply. This saves me money and I get better plants and better vegetables and fruit. I know what to buy and how much to use.

Where can I get a Soil Test Self-Mailer? Purchase at shop.msu.edu or some local Michigan State University Extension office have them for sale.

What kinds of tests are available? Your soil can be tested for use as a vegetable garden, lawn, trees, shrubs, flowers, tree fruit and small fruit—each are available as individual tests. For each purchased soil test, you can choose one kind of test. Each kind of test is designed for the crop or kind of test you select.

How much does this cost? A test and kit costs $25, which includes envelope and postage to send the kit to the MSU Soils Lab. You do not have to go to the post office; you just drop it in the mail box.

What do I get for my money and how long does it take? You receive an envelope containing a plastic bag for the soil that you will mail back, directions on how to take the soil and an information sheet to fill out and return. Your return envelope does not need postage. In about two weeks, you will receive an email with your recommendation.

What does it test for? This test is for nutrients like phosphorus, potassium, calcium and magnesium, soil pH and organic matter percentage. Your recommendation will include which nutrients are needed and in what amount per 1,000 square feet. Nitrogen will be included in the recommendation, if needed.

What does it not test for? Contamination, heavy metals or pollutants. It would be necessary to contact a private lab for specialized testing for these. A soil test for nutrients does not test for evidence of disease or insect problem or any sort of contamination.

How often should I get a soil test? Once every three years will give you the ability to see how much the soil has changed since you have been following your recommendation. You will also find out what you need to do differently like add less potassium or reduce the amount of organic matter you have been adding. Keep your tests and put them where you can compare them.

Are there certain amounts of nutrients or a soil pH that my soil should have? The nutrient amounts will be part of your recommendation, telling you what to add. A soil pH of 6.5 or in the vicinity works well for a vegetable or flower garden and a pH of 6.0 or slightly above for trees and shrubs. If the soil has five percent organic matter or a little higher, it is adequate.

If I have a question about my soil test recommendation, what can I do? Online, email your question through the Ask an Expert box on the www.msusoiltest.com webpage. Or by phone, call the Michigan State University Extension Lawn and Garden Hotline: 888-678-3464.

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