A soil pH meter is a handy tool that enables you to find out the pH of your soil so you can meet the needs of your plants' different preferred pH levels. You'll need to test the soil pH with the meter in all areas where you're growing plants, vegetables, trees, shrubs or grass. If you're testing the soil pH in your lawn, test the soil with the pH meter in several different areas to understand the differences in the soil pH throughout the lawn. The soil pH in any given area can change over time, as you apply fertilizers, as the plants process nutrients from the soil, from rain and watering, from herbicide and insecticide use and from mulching.
Water to moisten the soil in the test areas down to the depth of the plants' root zones. The soil must be moist in order for most meters to register the soil pH properly.
Insert the pronged electrodes of the pH meter into the soil. Insert the probe down to the root level beside existing plants or down to the expected root zone prior to planting.
Wait for the soil pH meter to calibrate and register the results on the device's screen, usually about two to three minutes. Write down the results to keep track of your soil pH readings in each location.
Adjust your fertilizer rates according to the soil pH test results. Add garden sulfur to lower the pH or lime to raise the pH, preferably during the dormant season or prior to planting. Test the soil again with the pH meter about four weeks after applying the pH amendments.