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The Role of Soil pH in Lawn Health and How to Adjust It

Posted on September 25th, 2023

Does your lawn sometimes look yellowish or pale green with stunted or slower-growing grass? Yellow colorations in lawn grass indicate acidic soil with a pH of 6 or lower. In contrast, a pale green indicates alkalinity with a pH of 7 or higher. The appearance of your lawn grass is a clear indication of the lawn soil’s pH, especially when it falls outside of the optimal range.

In this guide, you’ll learn about soil pH levels’ role in proper lawn care. Specialists from Turf Unlimited can provide valuable insights that can help you determine the signs of low or high pH levels and how to adjust them accordingly.

How Soil pH Can Affect Your Lawn

Maintaining the appropriate lawn soil pH levels helps to optimize nutrient availability, ensuring that essential nutrients are accessible to plants, promoting lush foliage and robust root development. Keeping pH levels within the appropriate range fosters a balanced soil microbial community, enhancing nutrient cycling and organic matter decomposition.

In addition, it also creates an environment where plants experience reduced stress and toxicity, resulting in healthier, more vibrant vegetation. Maintaining proper soil pH levels contributes significantly to thriving and resilient plant ecosystems.

Here are the ways soil pH can affect lawn health:

Ensuring Nutrient Availability

Maintaining the appropriate lawn soil pH influences the availability of essential nutrients to your lawn grass. Depending on several factors, different nutrients become more or less available at different pH levels. For example, when the soil becomes too acidic, with a pH below 7, nutrients like iron, manganese, and aluminum can become more accessible.

However, if you have more alkaline soils with a pH above 7, nutrients like phosphorus and potassium may become less available. It is important to note that when soil pH becomes too extreme in either direction, your lawn grass may get less nutrients. Extreme soil pH variances tend to cause nutrient deficiencies.

Maintain Grass Health

Experts recommend keeping lawn soil at a slightly acidic to neutral pH range, typically between 6 and 7, since most grass types thrive within this range. When the lawn soil pH falls outside this recommended range, it can have the tendency to stress your grass.

However, if the soil becomes too acidic, the pH falling below six can hinder root development and nutrient uptake. The impact on the roots can lead to stunted growth and yellowing. Conversely, when your lawn soil becomes too alkaline, above 7, it can limit nutrient uptake, impacting grass health.

Increased Weed Growth

It is important to note that weeds tend to thrive in soils with pH levels that are less favorable for your grass. For example, dandelions and similar weeds can thrive in alkaline soils, competing with lawn grass for essential nutrients.

On the other hand, other weeds, like sorrel, prefer acidic conditions. An imbalanced pH level can create an environment that encourages weed growth. With more weeds growing in your lawn, it makes it more difficult for your grass to obtain healthy growth.

Microbial Activity

Lawn soil pH levels also affect the activity of beneficial soil microorganisms, which play a crucial role in breaking down organic matter. It is important to note that soil bacteria and fungi help to improve soil structure, significantly impacting the cycling of nutrients. Extreme pH levels can disrupt the balance of these microorganisms, reducing overall lawn vitality.

Impact on Soil Structure

Soil pH can influence your lawn’s soil structure. Observe when your soil becomes too acidic. It tends to have finer particles. With this condition, your lawn soil becomes compacted quickly, which can lead to poor drainage and aeration. On the other hand, when your lawn soil becomes more alkaline, it often has larger particles, which can result in better drainage. However, having larger particles leads to reduced water and nutrient retention, which may require effective sprinkler installation.


Overseeding can be beneficial to your lawn but may impact soil pH. Using fertilizers with ammonium-based nitrogen sources can acidify the soil over time while lime-containing fertilizers can have an alkalizing effect. Make sure to adjust fertilizer levels and use appropriate seeding practices.

How to Test Lawn Soil pH Levels

Testing soil pH levels is crucial to maintaining a healthy and vibrant lawn. Here’s a step-by-step guide you can follow to test the soil pH levels:

  1. Choose the Right Time: The best time to test your lawn soil pH in the spring or fall. Avoid testing when the soil is too wet or dry since extreme conditions can affect pH readings.
  2. Gather Soil Samples: Use a garden trowel to collect soil samples from various lawn areas. Take samples from at least six spots for a good sample size, gathering the top 2″ to 4″ inch depths.
  3. Prepare Soil Samples: Remove any debris, rocks, or grass from the soil samples and place them in a clear container.
  4. Test the pH: Follow the instructions provided with your soil pH testing kit. Take a small amount of soil from each container and add distilled water to each sample, creating a slurry. Insert the pH indicator strip and allow it to sit for the recommended time. Compare the color on the pH strip to the color chart provided with the kit.
  5. Record the Results: Make sure to write down the pH level for each soil sample you tested. This will give you a good idea of the areas in your lawn with pH imbalances. Make sure to note any significant variations in pH levels across different areas of your yard so you can identify which spot needs work.
  6. Interpret the Results: As stated earlier, the ideal pH range for most lawns is between 6 and 7. This range provides optimal conditions for nutrient uptake by grass. Determine which areas of your yard need pH adjustments.

How to Balance Lawn Soil pH Levels

Taking immediate action after testing your soil’s pH levels is crucial. Based on your pH test results, you can make the necessary amendments to your lawn soil to bring it within the ideal pH range. Follow the soil test kit recommendations or consult with local lawn care specialists for guidance on adjusting your soil pH.

If the pH goes below 6.0, your soil is acidic, and you may need to add lime to raise the pH. However, if the pH is above 7.0, your soil is alkaline, and you may need to add sulfur or other acidifying agents to lower the pH.

You may need to retest your soil after making amendments. Wait several weeks or months, then retest your soil to ensure the pH has reached the desired range.

Trust the Lawn Care Experts from Turf Unlimited

Turf Unlimited has proudly served various counties in Massachusetts and New Hampshire since 1996. Our specialists provide reliable solutions, ensuring the perfect carpet of green for your property. Contact us today to get a quote.

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