How to Soil Test Your Lawn

closeup of a sand in hand

Never underestimate the power of soil. Your soil’s health determines the health of your grass and plants. But what if you don’t know how healthy your soil is? We’ll teach you how to soil test your lawn and find out what nutrients your turf is craving.

In this article, you’ll learn why it’s important to test your soil, ways to perform a soil test, and the pros and cons of each method.

Why test your lawn soil?

Your soil’s job is to provide nutrients to plants. Testing your lawn soil informs you on what nutrients and amendments your soil needs to perform at its best. A soil test can measure the following: 

  • Soil pH
  • Nutrient availability
  • Organic matter levels
  • Soil texture (percentage of clay, sand, and silt)

Soil pH and available nutrients can have a significant effect on lawn health. For example, if the soil’s pH is too high, nutrients like iron and phosphorus are difficult for plants to uptake. If your soil’s pH is too low, nitrogen, phosphorus, and potassium don’t dissolve well, keeping plants from absorbing them.

How to perform a soil test

illustration showing the pH levels of soil

There are two ways to test your soil’s health: using a soil test kit or sending a soil sample to a laboratory. Both options have different procedures, so we’ll outline their differences below.

Soil test kits

A soil test kit lets you see how healthy your soil is from your own home. A simple soil test kit can reveal whether your soil has a high or low pH. More complicated test kits assess your soil’s nutrient levels, particularly nitrogen, phosphorus, and potassium.

However, soil test kits aren’t always the most precise. Accuracy can vary from one test kit to another. Additionally, results usually don’t provide clear instructions on how to remedy the soil. For example, an at-home soil test might reveal your soil is low in nitrogen, but it won’t reveal how much nitrogen fertilizer to apply to fix the soil. 

● Reveals soil’s pH
● Shows whether nitrogen, phosphorus, and potassium levels are low, normal, or high
● Convenient and inexpensive
● Provides instant results
● Can be imprecise
● Doesn’t provide clear instructions on how to remedy soil
● Doesn’t determine if there are diseases in the soil

At-home soil test kit instructions

Because at-home test kits vary so vastly, it’s essential to follow your test kit’s instructions. Some tests are designed to measure pH, while others measure nutrient levels. 

You might also discover that different test kits come with different materials. Most test kits require distilled water, so have some on hand.

Here is a basic example of how to test your soil pH with a La Motte kit:

  • Collect your sample. Take your sample following your test kit’s instructions. Make sure to test different areas of your lawn, as results may vary depending on factors like underlying soil differences and localized conditions.
  • Dry your soil. You always want to take samples when the soil is dry, as wet soil can lead to inaccurate results. Spread the soil out on dry paper and let it dry.
  • Clean. Make sure your soil is evenly textured, and remove debris and rocks.
  • Fill and shake. Fill one of the test tubes to the fourth line with the pH indicator solution. Use the 0.5 grams spoon to add three scoops of soil to the tube and shake for one minute.
  • Settle. Set the test tube for about twelve minutes to let the mixture settle.
  • Compare. Standing with the sun behind you, compare the color of the mixture with that on the pH color chart.
  • Other tests. Follow the instructions to do tests for nitrogen, potassium, and phosphorus.

Sending to a lab

soil in hand

If DIY tests are too imprecise, consider sending samples to a soil testing lab. Not only can lab results reveal your soil’s nutrients and pH, but they can also provide fertilizer and amendment recommendations to manage your soil.

Most Cooperative Extension offices offer soil-testing services for low prices. If they don’t provide one, they can help you find a testing service familiar with soil in your location. Check with your local Cooperative Extension Office for more information.

Because soil tests vary by location, using the same office for multiple tests ensures consistency. Just be prepared to wait a few weeks to get your results.

Though lab tests are more accurate than DIY tests, the costs can add up if you need to do around four or five tests. Additionally, most labs, due to their agriculture-focused nature, recommend chemical fertilizers, which have the potential to increase your lawn’s acidity level and disrupt its pH balance.

● Reveals soil’s pH
● Provides fertilizer and amendment recommendations to remedy your soil
● Reveals precise nitrogen, phosphorus, and potassium levels
● Reveals other nutrient levels, such as iron and calcium
● While soil test kits often provide general measurements (low, medium, or high), lab results typically provide detailed measurements
● Though reasonably affordable, the costs can add up if you need to do multiple tests
● Often recommend chemical heavy fertilizers, which may make your lawn more acidic over time
● Not as convenient as a simple at-home soil test
● You may need to wait weeks before receiving results

Collecting a soil sample

soil sample
IAEA Imagebank | Flickr | CC BY-SA 2.0

Instructions for collecting a soil sample vary, as different labs have different protocols, so call and ask before gathering your soil sample. Nevertheless, most soil samples will be about the same:

  1. Clean. Clean the tools you’re using to collect the sample–– in this case, a shovel, a garden trowel, and a plastic container. Avoid collecting samples in metal buckets, as this may contaminate the soil sample.
  2. Make a map of your lawn. You’ll generally collect multiple samples in different areas to get an accurate view of all your soil. Try not to get soil from areas with fertilization or synthetic chemicals. Likewise, remove any thatch or vegetation from your soil.
  3. Dig. Dig a hole 6 to 12 inches deep. Mix up the soil in the hole, then take a cup of dirt and put it in the bucket.
  4. Collect. Repeat the above step in a zigzag pattern across the lawn, collecting about ten samples.
  5. Mix. Once you have collected your samples, use the hand trowel to mix all the samples together.
  6. Send. Place one to two cups in a labeled bag and mail it to a lab for analysis.

FAQ about soil testing

How much do laboratory soil tests cost?

According to the NRCS (Natural Resources Conservation Service), soil lab tests cost $7 to $10 per sample. The price varies depending on your state, the lab used, and the testing items (as more nutrients are analyzed, the cost increases).

How often should I test?

Test your soil at least once every three years. If you’re monitoring your soil after applying an amendment, test the soil every three to six months until you’ve achieved the desired nutrient or pH levels. 

When is the best time to collect soil samples?

You can take soil tests any time of the year as long as you avoid extremely wet soil conditions. 

Don’t soil your lawn’s health

Even after you get your soil test results, learning how to get healthy soil can be daunting. It’s very time-consuming to strike that perfect balance between air, organic materials, minerals, and micronutrients. 

If you aren’t patient, don’t worry about taking care of the lawn. Instead, contact a highly-rated professional in your area and have them take care of your lawn for you.

Main Image Credit: Pexels

Stuart Kushner

Stuart Kushner is a writer and aspiring product designer based in New York City. When he isn’t doing either, Stuart enjoys heavy metal music, exercise, and trying new food and drinks.