If you’re interested in lawn care, you’ve probably heard the term soil pH. You’ve also probably heard that you should regularly test your lawn’s pH level to check for imbalances.
Soil pH is a crucial component to track when measuring the well-being of your lawn. Like fertilizer levels and water drainage, pH significantly affects how well your grass grows and flourishes.
This lawn care guide will cover the basics of soil pH to help you maintain the greenest grass on your block.
Keep reading to find out:
- The importance of balanced soil pH
- How to test your lawn’s soil pH
- The best lawn treatment for pH imbalance
- How to maintain a neutral pH in your yard
What is Soil PH?
According to the Pennsylvania State University College of Agricultural Sciences, “the acidity or alkalinity of soil is indicated by its pH measurement.”
In more scientific terms, soil pH – which stands for potential hydrogen – is a measure of the ground’s hydrogen ion concentration. Soil pH decreases as hydrogen ions in the soil increase, creating a higher acidity level.
The pH scale ranges from zero to 14, with seven as a neutral point. Here is a pH scale from the U.S. Geological Survey Water Science School:
pH Level | Description | Examples of this pH level |
0 | Battery Acid | |
1 | Sulfuric Acid | |
2 | Vinegar Lemon juice | |
3 | Acidic | Soda Orange Juice |
4 | Acid rain | |
5 | Bananas Clean rain | |
6 | Milk | |
7 | Neutral | Pure water Saliva Blood |
8 | Seawater Eggs | |
9 | Baking soda | |
10 | Milk of Magnesia | |
11 | Alkaline | Ammonia |
12 | Soapy water | |
13 | Bleach | |
14 | Liquid drain cleaner |
You’ll see the terms low pH and high pH when testing your soil’s acidity and alkalinity levels.
- Low pH = Acidic
- High pH = Alkaline or basic
Why Does Soil PH Matter for Your Lawn?
Soil is a combination of minerals, micronutrients, and bacteria. These components work together to decompose organic matter and grow plants. Well-balanced soil pH is imperative to a healthy lawn and garden.
Nutrients in the soil must break down before plants’ roots absorb and use them. Soil pH affects how well nutrients can dissolve, making this measurement essential for successful plant growth.
Healthy soil contains a combination of the top three plant nutrients – nitrogen, phosphorus, and potassium, or NPK. Soil with a high pH is depleted of nutrient availability, which leads to poor growing conditions for grass.
Before you learn how to test your lawn’s soil pH, you must know which levels work for grass.
The SUNY College of Environmental Science and Forestry says “a pH range of approximately six to seven promotes the most readily available plant nutrients.” Soils with a pH level below four are high in metallic compounds and interfere with the growth of some plants.
You’ll need to consider different measurements if you plan to grow a broader range of shrubs or flowering plants. Some plants thrive in highly acidic or alkaline soil.
Examples of plants that like high pH soil: | Examples of plants that like low pH soil: |
Lavender Honeysuckles Lilac Forsythia Kale | Rhododendrons Blueberries Azaleas Potatoes Conifers |
Unlike the plants above, grass thrives in neutral soil with a pH level between 6.5 and seven.
If your lawn’s acidity level is too high, the bacteria in the soil won’t be able to properly process the organic matter that feeds the grass. The organic materials will be left to sit in the soil, creating a buildup of nitrogen. Excess nitrogen in your soil can cause fertilizer burns, leaving your lawn with dark green patches.
You might be interested in reading our article on DIY yard upkeep for a guide on how to maintain a healthy lawn.
3 Ways to Test Soil PH Value
Soil Test Kit
Perhaps the simplest way to test your soil’s pH level is with a test kit. Home improvement stores and garden centers sell soil tests for as little as $15.
Any kit you buy will provide detailed instructions to perform the most effective test possible. Most soil pH tests include a variation of the following steps:
- Dig a hole in the area you’d like to test, removing about three inches of soil.
- Clear any thatch or debris from the hole and fill it with distilled water. Distilled water is neutral and will provide the best results.
- Once the loose dirt in the hole has mixed with the water and become muddy, insert the pH test strip.
- Wait for a few minutes and then assess the test results.
We recommend testing your soil in a few different areas around your lawn. This method will give you a better understanding of which spots are neutral and which need soil amendment.
Digital Soil Tester
Digital meters are good for gardeners seeking a quick pH reading. These tools are available in most garden centers and provide an easy, accurate way to check your lawn’s pH.
If you want to test more than your soil’s pH value, select a multifunction meter that measures soil moisture, temperature, sunlight intensity, and more.
Digital pH meters are reusable, so you just need to recalibrate them between uses for accurate results.
Send a Sample to a Lab
Send a soil sample to a local testing facility if you’d rather let the pros test your lawn’s pH value. Many university extension offices provide soil testing services to the public.
The UF Institute of Food and Agricultural Sciences offers the following tips for sending in soil samples:
- If you’ve applied different fertilizers or treatments to other parts of your lawn, collect samples from each area.
- Do not take samples from problem areas like burn spots or puddles.
- If you don’t have a sampling tube or auger (soil drill), use a shovel to remove a 6-inch-deep wedge from the ground. Remove the center section of the wedge to send as your sample.
- Make sure you fill out all the appropriate paperwork, labeling sample containers/bags as necessary.
DIY pH Tests
You can also test the pH of your soil without a kit. A do-it-yourself method might not provide an exact pH scale measurement, but it can provide some helpful insight into the overall health of your lawn.
Vinegar and Baking Soda Test
Vinegar and baking soda are on separate ends of the pH scale, so they’re useful for measuring the baseline pH of soil.
For this DIY soil test, you’ll need:
- 2 cups of soil from your yard
- 2 empty containers
- ½ cup of white vinegar
- ½ cup of baking soda
- ½ cup of water
Follow these steps to test your soil’s pH value:
- Divide two cups of soil from your lawn into two separate containers.
- Pour half a cup of vinegar over one of the soil samples.
- If the soil begins fizzing, the sample has a high pH level.
- Test the other sample with baking soda if the soil doesn’t react to the vinegar.
- Mix half a cup of water into the soil sample.
- Combine the soil and water by stirring, and then pour in the half cup of baking soda.
- If the soil fizzes, it has a low pH value.
Red Cabbage Test
Red cabbage contains anthocyanin, a compound that reacts differently in acidic and basic environments. For this reason, the veggie provides a quick home remedy for testing pH value.
For this DIY soil test, you’ll need:
- A medium saucepan
- 5 red cabbage leaves
- 2 cups of distilled water
- Empty jar or clear container
- One tablespoon of garden soil
Follow these steps:
- Pour two cups of distilled water into a saucepan. Make sure to use distilled water, which has a neutral pH level.
- Chop up five red cabbage leaves. Add them to the saucepan.
- Bring the saucepan contents to a boil and then reduce heat to simmer for 10 minutes.
- Remove the cabbage water from the stove and let the mixture sit for 30 minutes.
- Strain off the liquid into a clear container. The water should be a purplish-blue color.
- Add a tablespoon of your soil into the water. Give it a good stir and wait 30 minutes.
- If the water turns pink or red, your soil is acidic.
- If the water changes to teal or green, the soil is alkaline.
- If the water stays purple or blue, your soil is neutral.
Next Steps
Once you’ve completed a soil test, you should better understand your lawn’s pH level. If your soil’s value was too high or low, don’t sweat. You can take several steps to get your soil back to balance.
The following sections will key you in on soil amendment and pH maintenance techniques.
How to Treat and Prevent Soil Imbalances
Grass does well in a neutral pH environment, so keeping your soil balanced is key. If you test your lawn and its value is too high or low, try a couple of tried and true methods to change your soil’s pH.
How To Treat Alkaline Soil
Use the following products to lower high-pH soil and improve low acidity levels.
Fertilizer
Fertilizers lower your soil’s pH value while supplying essential nutrients to your grass and garden.
Consider using organic fertilizer in your garden to neutralize pH, improve soil structure, and feed beneficial microbes. Select an ammonium fertilizer, which soil bacteria will process into acidic compounds.
If you decide to amend your soil’s acidity with fertilizer, monitor the amount you use per square foot. Fertilizers are primarily beneficial but can cause pollution and lawn damage when misused.
When selecting fertilizers, you’ll need to choose between organic and chemical options. Read our ‘Fertilizer Assessment: Organic vs. Chemical‘ article to help with your decision.
Peat Moss
If your soil has high pH and needs amendment, spread some peat moss around to aid in neutralization. Peat moss is an earthy material made of partially decomposed plants. This material is naturally acidic and neutralizes alkaline soils.
Peat moss is beneficial to a variety of soil types. It improves air circulation in dense clay and water circulation in dry, sandy loam. For this reason, peat moss is useful in many regions.
Elemental Sulfur
Sulfur is a naturally occurring element often used to make pesticides. It’s essential to nearly all bioprocesses, including healthy plant growth.
Elemental sulfur is an inexpensive and non-toxic way to lower your lawn’s pH value. Once mixed into the soil, sulfur is relatively slow to react, making it a good choice for pH maintenance.
Sulfur breaks down slowly in the dirt as bacteria decompose the element into sulfate. The element’s gradual discomposure makes it less likely to leach into groundwater supplies and harm wildlife.
How To Treat Acidic Soil
If your lawn is too acidic, add the following products to neutralize the soil’s pH.
Limestone
Use a granular lime product on your lawn to balance acidic soil and increase soil pH. Apply lime during fall or winter to neutralize the ground by the growing season.
Limestone is high in calcium carbonate, which has low water solubility. So, even if you water the soil after applying lime, it won’t absorb fully.
After liming, work the top few inches of the earth with a rake or hoe to get the best results, mixing the product down into the dirt. Apply slow-release lime pellets to maintain pH in a naturally acidic lawn.
Wood Ash
Wood ash is the powdery dust left behind after wood combusts. Wood ash is high in calcium carbonate, a “common liming material that increases soil alkalinity.”
Spread wood ash around your lawn and garden to neutralize acidic soil. Wood ash generally takes longer to produce results than limestone, so it’s a less popular “quick fix” method.
However, you can regularly apply wood ash to acid-prone soil to maintain a balanced pH level.
Final Thoughts
Soil pH is an essential component of healthy plant growth. Maintain your soil’s balance by incorporating pH tests and amendments into your regular lawn care routine.
If you test your soil and find a pH imbalance, you can use a variety of treatments to get your grass back to top condition. Once you determine your lawn’s alkalinity or acidity level, you’ll be one step closer to a well-kept, lush lawn.