Did you know that maintaining your soil’s pH level is important to ensuring a healthy, vibrant lawn? Even if you’re not super familiar with pH, the word might jog some old memories of high school chemistry class, when you used pH strips to determine whether different liquids, such as milk or lemon juice, were considered “acidic” or “basic.” If you left that knowledge in the past (probably along with how to calculate pi), no worries at all. We’ll cover everything you need to know about pH to keep your soil and its plants balanced and thriving.
We’ll cover what the pH levels in your soil mean, why they affect your lawn’s health, how to determine your soil’s pH levels, easy ways to adjust your pH lower and higher, how often to test your soil’s pH levels, and how to automatically and conveniently improve your pH levels over time.
What Is pH in Soil?
The pH levels in soil follow the same scale of alkalinity to acidity that you might’ve been testing in high school chemistry. Here’s a refresh: pH is scaled from the numbers 0 to 14. The number 7 is considered a neutral pH level, any number below 7 is considered an acidic pH level, and any number above 7 is considered an alkaline or “basic” pH level.
But it’s not just about getting a neutral, acidic, or alkaline pH reading for your soil. It’s about nailing that number perfectly—especially since the pH scale is what is called “logarithmic,” meaning that acidity or alkalinity exponentially grows from each number to the next. For example, a pH reading of 4 is 10x more acidic than a pH reading of 5, 100x more acidic than a pH reading of 6, 1000x more acidic than a pH reading of 7, and so on.
The actual number of your soil’s pH level is a big deal, and you want to get it just right. The ideal soil pH for vegetables and lawn grasses is 6.5, though some recommend anywhere between 6.0 and 7.0. Our advice? Get as close to 6.5 as possible and watch your vegetation grow strong, colorful, and abundant.
Why Does pH Affect Your Lawn’s Health?
So why does getting exactly the right pH levels in your soil make such a difference? That’s because the pH levels of your soil determine whether certain nutrients and minerals can be broken down and absorbed by your vegetation. And it’s estimated that if you don’t have proper soil pH, you’re wasting up to 75% of your lawn fertilizer’s essential nutrients because your soil simply can’t use them.
Nutrients such as nitrogen, phosphorus, and potassium, to name just a few, all help with different functions that allow vegetation to grow, from plant leaf development and chlorophyll production to assisting the process of blooming and fruiting, to aiding the overall strength of plants. Without proper absorption of all the nutrients necessary for a healthy lawn, a lot of problems will arise, from a lack of defense against pests and disease to a lack of growth, to insufficient root systems.
See for yourself in the chart below how many of the nutrients that benefit the health of your vegetation can only be absorbed within a certain pH range. Then, take a closer look at that 6.0–7.0 range. As you can see, most of these nutrients absorb well in those two columns.
Credit: Wikipedia Commons
How to Determine Your Soil’s pH
You’re probably feeling pretty ready to find out what’s happening below your soil’s surface. By testing your soil’s pH level, you can determine if your lawn is struggling due to an imbalanced pH. Thankfully, the process couldn’t be easier. All you need is pH test strips. You can even find some that are specifically designed for testing soil.
Once you have the test strips on hand, you’re ready to go. Here’s how you test the soil with test strips:
- Dig a narrow hole in your soil, about two to four inches deep.
- Next, move any twigs, rocks, leaves, or other debris to the side, then fill the hole with distilled water. This type of water is neutral and neither acidic nor alkaline.
- Once you fill the hole with water, it will turn into a muddy pool, pulling in the soil from around the hole. Once it seems sufficiently muddy, but still liquid, insert the test strip.
- Depending on the test strip manufacturer, you’ll get results after around thirty seconds to a minute.
- Repeat the process across your yard to determine how consistent (or inconsistent) the pH level of your soil is, depending on where you’re testing.
Remember, if your soil pH level is lower than 7, that means your soil is acidic. If it’s higher than 7, it means it’s alkaline. If it’s 7 on the dot, it’s neutral. You’re trying to hit the number 6.5, or at least between 6.0 and 7.0.
If your test strips have specific instructions, be sure to follow them.
How to Adjust Your Soil’s pH
Now that you’ve tested your soil’s pH level, you know whether it needs to be raised or lowered. (And if it’s just right, lucky you!) Thankfully, there’s no shortage of ways to rebalance your soil’s pH, and you have chemical and natural options.
How to Lower Your Soil’s pH
If your soil’s pH level tested over 7.0, it’s time to push that number back down. Here’s how to make your soil more acidic.
Compost and Coffee Grounds: These effective methods are organic and allow you to lower your soil’s pH while repurposing household materials that would otherwise be thrown into the trash. To apply compost or coffee grounds into your soil, it’s best to sprinkle them on top (make sure that compost is broken up into manageable pieces) and then mix it into the soil about a foot deep.
Sulfur: Often cited as the easiest way to lower soil’s pH level, sulfur is cheap, relatively safe, and can even be spread right on top of the soil. Just keep in mind that this method is pretty slow-acting, and its effectiveness builds over time.
Peat Moss: A decomposed organic material salvaged from peat bogs, this type of moss is an organic and simple way to lower your soil’s pH. Just soak your peat moss in some water and let it sit until it’s moist. Then, remove it, give it a squeeze to remove excess water, and mix it into your soil at a ratio of 1:1.
How to Raise Your Soil’s pH
Ready to bump up that pH a bit? Here are some of the methods to make your soil more alkaline, effective, and easy.
Limestone: A common soil additive for raising pH, limestone is usually organized into two types: calcitic limestone and dolomitic limestone. While both work equally well at raising soil pH, it’s important to keep in mind that dolomitic limestone also adds magnesium to the soil, which can be beneficial. You can find limestone in granular, hydrated, pelletized, or pulverized forms. No matter the form, all lime additives work better if they can be worked down into the soil, such as during the lawn aeration process.
Crushed Eggshells and Wood Ash: Raise your soil’s pH and recycle some household items while you’re at it. Simply add crushed eggshells or wood ash to the top of your soil and mix it in about a foot deep. An extra plus: these organic materials will break down without harming any of the beneficial microorganisms that live in your soil. Can’t say the same for some chemical pH-raisers!
How Often to Test pH in Your Lawn’s Soil
There are four factors that tend to lower the natural pH of your soil: climate, vegetation, topography, and time. On the other hand, some agricultural activities end up inadvertently raising your soil’s pH. Since your soil is a delicate ecosystem and you don’t want its pH to slip for long, it’s important to test the pH in your lawn’s soil often.
So get comfortable with those test strips. Or, you can also go automatic.
Or, Test Your Lawn’s Soil… Automatically
One way to defend against a shifting pH in your soil is to use an automatic lawn treatment. The OtO device monitors real-time local and regional weather, windspeed, humidity, and temperature data, and uses this data to adjust when it delivers treatments to your lawn, including irrigation, natural fertilizer, tick and mosquito control, and more. The result? The improved health of your soil over time, and a more consistent pH level across your healthy, lush yard.