Remember back in science class where you had to test various liquids to check their pH level with that magical strip of paper that changed color if it was acidic or alkaline? Or perhaps you’ve already dabbled with pH adjustments with your pool’s maintenance? Well, it turns out that the soil’s pH level also has a great impact on the health of your lawn.

But how does pH affect the lawn?

As it turns out, whether your soil is too acidic (below 7.0) or too alkaline (higher than 7.0) affects the survivability of both the turfgrass and shrubs. Optimal soil pH for turfgrass, shrubs, and flowers to thrive is between 6.5 (slightly acidic) and 7.0 (neutral). Some areas are by default more acidic than others due to environmental conditions even if they are in the same region. For instance, although both locations are in East Texas, areas around Lake Livingston have more acidic soil than areas closer to Houston, such as Porter and Kingwood, due to the large population of pine trees around the lake.

Detrimental Effects of Soil Acidity

When soil acidity is not properly controlled, the effectiveness of fertilizer use and lawn performance is reduced. Areas with large amounts of rainfall tend to have more acidic soils by leeching basic elements, such as calcium, potassium, sodium, and magnesium, from the soil profile, leaving behind the acidic elements.

Remember all that rain we’ve had this year?

The greater the intensity and duration of the rainstorm, the higher the erosion potential. Soil erosion caused by wind and rain is another contributing factor for increasing levels of soil acidity, not to mention that hydrogen ions are also excreted from soil microbes in exchange for nutrients in the soil. As the amount of hydrogen in the soil increases, the soil pH level decreases, making the soil more acidic.

Undesirable pH level can cause limited availability of some macronutrients and micronutrients by locking up nutrients and preventing them from being absorbed into the soil and root system. Essentially, as pH level drops below 5.5 and becomes more acidic, beneficial microbial activity is reduced by elemental toxicities that have increased solubility at low pH values, such as aluminum and manganese, and becomes toxic to the plant’s root growth.

The lack of prosperity for the soil microbes affects the breakdown of organic compounds and mineral nutrients found in the soil that rely on the microorganisms to decompose. Not only do soil microbes perish in non-preferred pH levels, lawns will be more susceptible to diseases, weeds, and even insect population won’t be kept in checked. And with their increased acidity tolerance, fungi will become more prevalent in acidic soils compared to bacteria.

So what’s the remedy?

For acidic soils, the pH level can be increased by the addition of lime-like amendments that have been grounded fine for use, such as dolomitic limestone, to rid the soil of hydrogen ions and encourage beneficial microbial activity. As the soil pH level increases, excess metals, such as aluminum and manganese, will precipitate.

Lime applications can be done by one of our licensed technicians or yourself if you’re DIY savvy.