There are two ways to soil test your lawn: sending your soil to a professional lab and using a DIY testing kit. The first step for either method is to gather a clean soil sample.
Two ways to test your soil: Lab and DIY
The two ways to test your soil – lab testing and DIY testing – both have their merits.
Lab soil tests are more precise but less convenient. When it comes to professional lawn soil testing, you have two options. You can send a soil sample to a private soil laboratory or your local Cooperative Extension Office. Here are its pros and cons:
| Pros of lab soil tests | Cons of lab soil tests |
| ✓ More accurate ✓ Reveals exact soil pH ✓ Reveals precise nitrogen, phosphorus, and potassium levels ✓Shows micronutrient levels ✓ Provides fertilizer and amendment recommendations to remedy your soil | ✗ Can be more expensive if you need to do multiple tests ✗ May recommend chemical-heavy fertilizers, which have an acidifying effect ✗ Not as convenient ✗ May take weeks to receive your results, especially during peak seasons of spring and fall |
Two of these cons can be mitigated, though:
- Ask your local Extension Office if they offer soil-testing services as many of them do so at a lower cost. Check with your local Cooperative Extension Office for more information.
- Test your soil the season before your lawn’s peak growth season so you have enough time to get the results before you have to apply fertilizer and amendments. The Louisiana State University AgCenter even recommends testing your soil during late fall or early winter for quicker results.
DIY testing is faster and cheaper, but less reliable than professional soil testing. Let’s go over its pros and cons:
| Pros of DIY soil tests | Cons of DIY soil tests |
| ✓ Provides instant results ✓ ConvenientTends to be cheaper | ✗ Less accurate ✗ Doesn’t provide clear instructions on how to remedy soil |
How to test your soil through a lab (step-by-step)
Professional soil testing involves shipping a clean, dry soil sample to your lab of choice. You will need to send your soil in a plastic container or a baggie. Sometimes, the lab will provide sample bags for you to ship the soil in.
Not just any soil will do. Different soil testing labs may have different protocols, so it’s better to call and ask. However, the process is usually pretty similar. Just make sure you’re gathering soil that isn’t wet from rain or irrigation. Wet soil will give you an inaccurate result.
Let’s first go over the tools and materials you will need:
- Shovel or soil probe
- Garden trowel
- Plastic container or baggie
- Plastic bucket
- Newspaper
Make sure your tools are clean and rust-free. You want to use plastic containers as metal may contain traces of micronutrients that can contaminate the samples. The North Carolina State University Extension recommends using stainless steel or chrome-plated tools, as well as avoiding brass, bronze, or galvanized tools.
Here’s a step-by-step guide on how to test your soil through a lab:
1. Map out where you’ll take soil samples.
You’ll want to take soil from different spots on your lawn to get an accurate profile of your soil. Most labs recommend taking soil from 10 to 15 spots. However, you should keep these tips in mind:
- Don’t take soil from treated soil. In other words, don’t take freshly fertilized and amended soil. It’s fine to take samples from soil that you fertilized and amended months before – in fact, that’s how you track soil pH and nutrient level changes.
- Don’t take soil from an area close to water if you are taking samples from other areas not close to water.
- Don’t mix soil from your lawn and soil from your garden or other areas with ornamentals or edibles. For the most accurate results, do a separate soil test for these areas.
Generally, you want to avoid mixing soil from areas with different characteristics. For example, your lawn’s soil will likely have different characteristics from your garden’s soil. If you use different fertilizers in two areas, it’s best not to mix samples from those areas.
2. Collect your soil samples.
For lawn soil tests, you’ll need to take soil from the top 2 to 4 inches. When in doubt, ask your soil lab of choice for clarification.
Go to one of the spots you have marked for sampling and start digging using your shovel. You can also take a soil sample using a soil probe.
After taking out the soil, remove organic material from it such as:
- Thatch
- Roots and other plant material
- Mulch
- Earthworms and other bugs/pests
Then, place the now-clean soil in your clean, plastic bucket.
Repeat this process for each area you intend to sample.
3. Mix the soil samples and let dry.
Using your trowel, mix up the soil samples in the bucket. You want to mix it well to get a final soil sample representative of your lawn’s overall soil condition.
Then, take about a cup or two of the mixed soil and spread it out on the newspaper. Let it dry out at room temperature and protect it from moisture.
4. Send the final soil sample.
Take the final dry soil sample and place it in the container provided by your chosen soil laboratory. If there was none provided, use a plastic container or baggie.
Label the container and mail it to the lab for analysis.
How to test your soil DIY (step-by-step)
If you want quick results, you can buy a DIY home soil test kit from a garden supply store or a hardware store. A simple soil test kit can reveal whether your soil has a high or low pH. More advanced test kits assess your soil’s nutrient levels, particularly nitrogen, phosphorus, and potassium.
You’ll need the following tools and materials to test your soil DIY:
- Shovel or soil probe
- Garden trowel
- Plastic bucket
- Newspaper
- Distilled water
- Soil testing kit
Most of these materials are the same as that of lab testing. That’s because testing with an at-home soil test kit starts with getting a clean soil sample.
Here’s a step-by-step guide on how to test your soil DIY:
1. Read the instructions of your soil testing kit.
Each soil testing kit works a little differently, so it’s best to read the instructions that come with your chosen kit.
2. Collect your soil sample.
We’ve already covered how to get a clean soil sample above in the lab testing section. You collect samples the same way. Here’s a shortened version:
- Determine suitable soil sampling sites without chemicals like fertilizer and soil amendments.
- Go to one of these sites and dig up soil from the top 2 to 4 inches of ground.
- Remove thatch, mulch, worms, and other organic material.
- Repeat for each spot on your lawn.
- Mix the soil in a bucket.
- If moist, dry out the soil on a piece of newspaper.
3. Fill the test container with soil.
Fill the test container with soil. How much you need to add will depend on your specific testing kit. You will also need to mix in something else, like a solution or a pill.
Then, shake the testing container. Leave the mixture alone until it settles.
4. Read your results.
Compare the color of the liquid to the color chart that came with your chosen test kit. It might also be on the container itself.
The color chart can tell you how basic or acidic your soil is. It may also tell you about your soil’s nutrient levels.
Other types of soil tests
There are other types of soil tests you can do at home. They don’t need any special equipment:
- Tests to find out soil composition:
- Squeeze test
- Ribbon test
- Jar test
- Percolation (drainage) test
- Tests to check for organisms:
- Worm test
- Grub test
- Pantry soil pH test
Squeeze test
You can have different types of soil on your lawn. The most common ones are sandy soil, clay soil, and loamy soil. You can do the squeeze test to get an idea of what type of soil you have:
Here’s how to do the squeeze test:
- Take some moist soil.
- Squeeze it hard, then let go.
- Observe what happens to your soil:
- If it holds its shape but crumbles when disturbed, then you most likely have loamy soil.
- If it holds its shape even when disturbed, then you most likely have clay soil.
- If it falls apart immediately after letting go, then you most likely have sandy soil.
Ribbon test
You can also figure out what your soil is made of with the ribbon test. You’ll need some water for this test.
Here’s how to do the ribbon test:
- Grab a handful of soil.
- Remove rocks and organic matter.
- Lightly spray some water on the soil and knead until it feels like putty.
- Roll the soil into a ball. If it doesn’t form a ball, you have sandy soil and you can skip to Step 6.
- Once you have a ball, push the soil over your fingers with your thumb to form a soil ribbon.
- If your soil ribbon crumbles easily, you have loamy soil.
- If your soil ribbon gets long, you have clay soil. The longer the ribbon, the more clay your soil has.
- Then, feel the soil in your hands:
- If it feels gritty, you have sandy soil.
- If it feels silky like flour, you have soil with a lot of silt.
- If it feels sticky, you have clay soil.
Jar test
The last way you can find out what your soil is made of is the jar test. This requires a bit of math, but it will give you a more exact look at the composition of your soil. You’ll need a straight-sided jar (with a lid), some water, a marker, a ruler, and a timer.
Here’s how to do the jar test:
- Get a soil sample by digging down 6 inches into the soil.
- Fill the jar one-third of the way with soil.
- Fill the rest of the jar with clean water, but don’t fill it up all the way.
- Close the jar and shake until the soil fully mixes with the water.
- Put the jar on a level surface and set your timer for 1 minute.
- After 1 minute, you should see a layer of sediment. This is the sand in your soil. Mark the outside of the jar to denote the top of the sand layer.
- Set your timer for 2 hours and leave the jar alone.
- After 2 hours, you should see another layer of sediment on top of the sand. This is the silt in your lawn soil. Mark the outside of the jar to denote the top of the silt layer.
- Leave the jar alone for 48 hours.
- You should see another layer on top of the silt. This is the clay in your soil. Mark the outside of the jar to denote the top of the clay layer.
- Measure the height of each layer with a ruler. Then, measure the total height of all the layers. You will always get three layers as soil is a mix of sand, silt, and clay. The difference lies in how big the layers look; some may look very thin and almost invisible.
- Get the percentage of each layer with this formula:
Percentage: (height of layer / total height) x 100
Let’s see what the formula looks like for a jar with 4 inches of sand, 2 inches of silt, and 1 inch of clay (a total of 7 inches).
Sand percentage: (4 inches / 7 inches) x 100
Sand percentage: (0.5714) x 100
Sand percentage: 57.14 or 57%
Do the same for the silt and clay layers. So, soil with a sand layer of 4 inches, a silt layer of 2 inches, and a clay layer of 1 inch is 57% sand, 29% silt, and 14% clay.
You can use these results to find out what type of soil you have by plugging their values into the soil textural triangle. In this case, the example I used above is sandy loam soil.
The lines going upward from right to left correspond to the percentage of sand, those going downward from left to right are for the percentage of silt, while the horizontal lines are for the percentage of clay.
You can use your soil texture to determine what soil amendments might benefit your soil.
Percolation (drainage) test
Also called a perk test, a percolation test can tell you your soil’s drainage capability. Knowing how well your soil retains water can help you adjust your lawn irrigation. You’ll need a lot of water, digging tools, a yardstick, a bit of math, and lots of time.
Here’s how to do a percolation test:
- Wait for clear weather. You want to do this test when it hasn’t rained in a few days.
- Dig four holes all around your yard about 1 foot deep and 4 to 12 inches wide.
- Fill the holes with water, making sure not to wash soil into the hole while doing so.
- Keep the holes filled for at least 4 hours (ideally, overnight) by adding more water. This will saturate the soil. If the water completely drains less than 10 minutes after filling a hole, fill it again. If it happens again, proceed to step 5c.
- Check the holes for water:
- If a hole has water, add water so that it’s 6 inches deep. After 30 minutes, measure how much water was lost with your yardstick.
- If the hole has more than 6 inches of water, then you will need to let it drain or redo the test on another day as it means that it has rained or your irrigation system has filled the hole, disrupting the test.
- If a hole has no water, refill the hole with water so that it’s 6 inches deep. Measure how much water is lost after 30 minutes, then refill until the water is 6 inches deep again. Repeat until 4 hours have passed (eight total measurements).
- If you skipped to this step, you will need to refill the hole with water up to 6 inches deep. Measure how much water is lost after 10 minutes, then refill until the water is 6 inches deep again. Repeat until an hour has passed (6 total measurements).
- Calculate the percolation rate by dividing the time interval (either 30 minutes or 10 minutes) and the drop in water level (how much water was lost). Use the last measurements you recorded.
Percolation rate (mpi): Time (in minutes) / drop in water level (in inches)
For example, if your soil drained 0.5 inches in 30 minutes, you do this:
30 minutes / 0.5 inches = 60 minutes per inch (or 1 inch of water per hour).
7. Calculate your lawn’s percolation rate by getting the average of the percolation rates you calculated for each hole.
Ideally, your soil should drain 1 to 3 inches of water per hour. Anything less than 1 inch per hour is poor-draining soil, and anything more than 4 inches per hour is very well-draining soil – perhaps even too well-draining.
Worm test
This test is an easy one, but not for the squeamish. You want to do this on a cool, but not cold day; ideally, the temperature should be around 55 degrees Fahrenheit. The soil should be moist, too. You’ll need some cardboard, a digging tool, and gloves.
Here’s how to do the worm test:
- Dig a hole about 1 foot wide, 1 foot long, and 1 foot deep.
- Place the soil you just dug up on some cardboard.
- Carefully go through the soil. Take note of any worms you find. You can put them in a container with some soil.
- Count the total number of worms you have collected.
- Place the soil back in the hole. Place the worms on top of the soil.
A variation of this is provided by Christina Curell, a soil health educator with the Michigan State University Extension. You’ll just need a solution of 2 tablespoons of mustard dissolved in 0.5 gallons of water. After digging the soil, slowly pour the solution. After 5 minutes, you should see some worms. Add them to the jar and count.
Curell also provides a different method to count worms without digging into the soil. You’ll need 2.5 gallons of the mustard solution and a bit more time, though. Here’s how to do it:
- Mark off a square foot of soil on your lawn.
- Slowly pour the mustard solution into the soil. It should penetrate the soil and make it saturated. This will take a few minutes.
- Collect the earthworms that burrow to the surface. Continue watching for earthworms for 10 minutes.
- Count how many earthworms you have collected.
Earthworms can tell you how much organic matter is in your soil. Finding less than 10 worms means your soil has very little organic matter in it. It may benefit from soil amendments.
Read more:
Grub test
Do you suspect you have white grubs on your lawn? You can actually do a simple test to check if you have a grub problem. However, you’ll need to get down and dirty, as well as get comfortable touching grubs. You’ll need a shovel or lawn edger and some gloves.
Here’s how to test your soil for grubs:
- Cut up a square foot of your lawn using the shovel or lawn edger. Be careful not to cut the roots out.
- Remove the grass from that square foot you cut out. If your lawn has grub damage, it’ll practically peel off from the ground.
- Sift through the soil in the patch you just removed grass from.
- Pick up and count any grubs you find. Consider putting the ones you’ve accounted for in a glass jar.
- If you find five (5) or more grubs, you have a grub problem. Finding 10 or more grubs means you have a severe grub infestation that needs to be addressed ASAP.
- If you find less than five (5) grubs, don’t worry. A few grubs won’t hurt your lawn.
- Replace the grass patch you removed as soon as you’re done checking for grubs. If done properly, the grass should continue to grow without issue.
You can check multiple patches of grass if you’d like to be sure.
Note: Don’t do this on dead or dying grass as you might not find a lot of grubs in severely damaged areas.
Related articles:
Pantry soil pH test
You can use vinegar and baking soda – two very common pantry ingredients – to test the pH of your soil. It’s not going to be precise, though. It will only tell you if your soil swings one way or the other on the pH scale.
Here’s how to test your soil pH with pantry staples:
- Dig up two chunks of soil.
- Mix a solution of 1 part vinegar to 1 part water.
- Add the vinegar solution to one chunk of soil.
- If it fizzes, then your soil is alkaline.
- If it doesn’t fizz, proceed to Step 4.
- Mix a solution of 1 part baking soda to 1 part water.
- Add the baking soda solution to the other chunk of soil.
- If it fizzes, then your soil is acidic.
- If it doesn’t fizz, your soil is likely neutral.
Again, this won’t tell you how acidic or how basic your soil is. It’s better to use a soil pH test if you need to find out your soil’s exact pH level.
FAQs about how to soil test your lawn
What does a soil test tell you?
Your soil test report will look different based on the tests you have done. However, many soil tests will tell you one of these things:
- Soil pH levels (precise or range)
- Nutrient levels (precise or range)
Lab tests will tell you more about your soil, like its organic matter level and salinity. A professional soil test may also recommend fertilizers and amendments to fix soil issues you have.
What is the most accurate way to test soil?
The most accurate way to test soil is sending your soil to a professional soil lab. You can send your soil to a private soil lab or inquire about soil testing services at your local Cooperative Extension office.
How often should you test your soil?
If you have healthy soil, you should test your soil every 3 to 5 years just to check up on it.
However, you’ll need to test your soil if you’re having lawn problems just to rule out pH imbalances and nutrient deficiencies.
If you have applied amendments to change your soil pH or fertilizers to boost nutrient levels, you’ll need to test your soil every year (perhaps even more often) to track the changes in your soil.
Hire a lawn care professional
Soil health is just one factor affecting your lawn’s overall health. You also need to keep up with mowing, fertilization, and weed control. If you would like some help with lawn care, consider hiring one of Lawn Love’s lawn care pros. We have pros all over the country, so we’re bound to have one near you.
Read more about soil pH:
- “Signs Your Lawn Needs Lime”
- “8 Plants That Like Acidic Soil”
Sources:
- North Carolina State University Extension
- Louisiana State University AgCenter
- Michigan State University Extension
Main Image Credit: Pexels
