How to Lower pH in Lawn Soil
Lawns typically prefer a pH between 6.2 and 7.0. Any number above 7.0 indicates excess alkalinity that may deter your grass from properly absorbing nutrients and minerals. Read more about how to lower pH in lawns and grow grass in alkaline soil.
Signs of High pH in Lawn
If your lawn is showing signs of stress despite regular care, high soil pH may be to blame. Alkaline soils—those with a pH above 7.0—can interfere with nutrient availability, leaving grass looking pale, patchy, or slow to grow. You might notice more weed problems or a hard, compacted soil surface that resists water and root development. Weeds like plantain and knotweed thrive in these conditions, while your grass struggles to absorb essential minerals like iron and phosphorus. Testing your soil is the first step to identifying this issue and taking action to restore balance.
Test Your Soil
A soil test kit will let you know if your soil has a low, neutral, or high pH.
Our easy-to-use Soil pH Test Kit for Lawns determines pH levels in just five minutes. The kit includes one test tube, one capsule of powder, and one pH range color chart to help you identify the results.
It is important to use either distilled water or rainwater when using this test kit in order to get accurate pH readings. Tap water has been pH-adjusted by municipal water authorities and will affect the reading.
Alternatively, try Jonathan Green’s Pro pH & Moisture Soil Tester, which accurately measures soil pH and moisture levels to within 0.2 pH and a 10% moisture level in just two minutes. This high-quality professional tool is used by sod growers, golf course superintendents, sports field managers, and landscapers to determine the right time to add fertilizer and lime.
Lowering pH in Soil
If your soil is too alkaline (pH above 7.2), you will need to lower the pH.
When soil is too alkaline and compacted, air, water, and nutrients cannot get down to the roots, and the grass will not grow properly. In soils with pH readings of 7.0 to 9.5, weeds thrive and the grass becomes light green and spindly.
Jonathan Green’s Mag-I-Cal® Plus for Lawns in Alkaline & Hard Soil lowers pH and loosens hard soils. The active ingredients are sulfur and calcium sulfate dihydrate. They help balance soil pH, are important for cell development, and are vital to many grass plant functions.
Mag-I-Cal® Plus also helps to break up clay and compacted soils. This improves root penetration and promotes grass plant growth by increasing biological activity and releasing nutrients that are trapped in the soil.
Apply Mag-I-Cal® Plus Soil Food to a dry lawn during spring, summer or fall when the soil is not frozen. It can be used when seeding or sodding and is safe for use around children or pets.
About Jonathan Green
Jonathan Green is built upon time-honored tradition and innovative scientific research. For six generations, we have studied turfgrass and what it needs to thrive. Using the latest scientific technology, we test all of our products to ensure that they will perform as expected on your lawn. Our mission is to help you create a beautifully green, healthy space for your family. To learn even more, check out our article on the importance of grass soil pH.
