how often to repeat soil test - Ask Extension
If we added fertilizer to our soil this year based on the recommendations of the 2026 soil test, when would you recommend repeating the soil test?
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Knowledgebase
how often to repeat soil test #930366
Asked May 02, 2026, 9:42 AM EDT
If we added fertilizer to our soil this year based on the recommendations of the 2026 soil test, when would you recommend repeating the soil test?
If we add the recommended fertilizers to our lawn this year, is this something we should do on an annual basis and in the same amounts?
If we add potash to the starter fertilizer, will that change the pH of the soil?
Wayne County Michigan
Expert Response
Hello,
MSU recommends repeating your soil test every three years for turf, following the last soil test recommendations each season for those 3 years. You can wait longer between tests for trees and shrubs and perennials.
Some potash fertilizers have a “liming effect” that can raise soil pH. Follow your soil test recommendation if you need to alter soil pH. Potassium hydroxide and wood ash can significantly raise pH, while potassium chloride (muriate of potash) has a more neutral effect.
Always follow the test results, dividing the fertilizer applications so that you do not exceed the recommended amount at any one time. MSU give you the total amount for the season, which you divide according to the chrt shown at the bottom of the report for lawns.
If you are attempting to change your soil pH you can test once every 12 months to monitor the change. Changing soil pH is a long process.
Finally, please read and follow all precautions and directions on the label of any products you use. By law, the label tells you what amount, and how to apply the product safely.
MSU recommends repeating your soil test every three years for turf, following the last soil test recommendations each season for those 3 years. You can wait longer between tests for trees and shrubs and perennials.
Some potash fertilizers have a “liming effect” that can raise soil pH. Follow your soil test recommendation if you need to alter soil pH. Potassium hydroxide and wood ash can significantly raise pH, while potassium chloride (muriate of potash) has a more neutral effect.
Always follow the test results, dividing the fertilizer applications so that you do not exceed the recommended amount at any one time. MSU give you the total amount for the season, which you divide according to the chrt shown at the bottom of the report for lawns.
If you are attempting to change your soil pH you can test once every 12 months to monitor the change. Changing soil pH is a long process.
Finally, please read and follow all precautions and directions on the label of any products you use. By law, the label tells you what amount, and how to apply the product safely.
