How to Test Soil pH: Easy Garden Guide

The right soil pH level can make all the difference for plants to grow, but if I asked you what your soil's acidity or alkalinity is, would you know without testing it? You could purchase test strips or send a soil sample off to be tested, but what if I told you that there is a simple way to know soil pH just by looking at it?

In this guide, I'll show you how to test soil pH at home with this simple DIY method and how to use a kit if you need to get precise results.

Why Soil pH Matters

Soil pH plays a pivotal role in a plant’s ability to uptake the nutrients it needs. Any extreme too low or too high will affect the solubility of nutrients and, therefore nutrient uptake as well.

We all want to have a garden that thrives with low maintenance. Knowing the pH of your native soil and understanding soil composition gives you a baseline for amending your soil to reach that goal.

Regardless of what pH you start with or which gardening methods you use, I recommend using compost as a pH buffer that will also improve soil structure and fertility.

What Is pH?

The pH scale measures how acidic or alkaline a substance is. It ranges from 0 to 14, with 7.0 being a neutral pH. A pH higher than 7 is alkaline, and a pH lower than 7 is acidic.

All soil has a pH and all plants (and even worms and microorganisms) will have an optimal range for their health. The following things have a strong impact on your soil pH:

• Native Soil Type - As you will see in the chart below, your garden's native soil type will dictate its predominant pH.

• Rainfall - You may already know that water passing through soil can remove nutrients, but rainfall also causes chemical reactions to take place, which form more acid in your soil.

• Fertilizers & Amendments - Nitrogen-based fertilizers make the soil more acidic, while lime makes the soil more alkaline.

• Compost - Organic matter helps keep the pH stable and finished compost helps move the pH closer to neutral.

When to Test Soil pH

It is always a good idea to test the soil pH when starting a new garden or moving a raised garden bed to a new location. While soil testing can take place any time of the year, it is often done in the fall to allow time for amendments to correct any issues.

Even through rainfall, fertilizing, and amending affect soil pH, I usually repeat the same soil amending regimen each year, and I do not retest throughout the growing season to make pH adjustments. Trying to keep an exact pH consistent throughout the growing season is a lot of extra work for very little output increase.

The cold-weather crops that I am growing early in the season do well with the slightly more neutral to alkaline soil that I have in the spring. And the late summer crops, like tomatoes and peppers, can handle the more soil acidity that comes from the applied fertilizers and rainfall throughout the season.

Pro-Tip: The preferred pH level that I amend for in my garden soil is slightly acidic at 6.0 to 6.5. This pH is hospitable for most plants. Aim for this goal when amending garden soil unless you are growing a specific crop like blueberries that has unique pH needs (a pH of 4.2 to 5.5).

How to Test Soil pH Without a Kit

As you may know, I grew up near an Amish community where most Amish families center their lives around their farms. I have talked with many of them and watched their gardening and farming practices.

One day, I was speaking to an Amish gentleman and asked him how to test soil pH. His answer really rocked my world. He said that he just looked at it to know the pH!

He taught me that by looking at the color of the soil and the texture, you can know the pH range associated with that.

How to Test Soil pH With a Kit

Before learning how to test the soil pH by sight, I would use pH test strips, a pH probe or send my soil off to a soil testing lab. I have gotten great results that way. If you are looking for very specific results, testing with a kit is the route you should go.

The Rapitest Soil Tester is an excellent kit to remove the guesswork from pH adjustment. Here are the step-by-step instructions for using it to test your soil.

Materials Needed

• Hand Trowel or Gloves - To avoid tainting the results by touching the soil with your hands, you will need a small spade or clean gloves to dig and remove the soil for your test.

• Rapitest Soil Test Kit - The testing kit includes 10 tests each for pH, nitrogen, phosphorus & potash.

• Water - Preferably, use distilled water because it has minimal impurities that can interfere with an accurate result.

• Soil - Select soil from the garden you want tested that is free of debris or organic matter.

How to Test Soil pH Step-by-Step

1. Take a soil sample from 2 to 3 inches below the surface using clean gloves or a tool to avoid touching soil with your hands.

2. Remove the cap from the green test chamber and make sure the color chart (film) is in place.

3. Place the soil sample in the green test chamber up to the soil fill line.

4. Carefully break the green capsule included in the test and pour the contents into the test chamber.

5. Using the dropper provided in the test kit, add distilled water up to the water fill line.

6. Fit the cap on securely and shake thoroughly.

7. Allow the soil to settle for one minute.

8. Compare the solution's color with the pH chart included in the test kit. Pro-Tip: For the most accurate color comparison, read the test results in a well-lit place with plenty of daylight but not direct sunlight.

How to Correct Soil pH

Amending with compost is great for moving soil toward a neutral pH and improving overall soil health. I recommend learning how to make compost at home or vermicomposting. Once the compost is fully mature, apply compost as a mulch layer on top of the soil with a no-till gardening approach.

If your soil is too acidic, you may need to add lime. Lime is a natural soil amendment that can help raise the pH level. A soil pH test should be done to ensure you are not adding too much.

If your soil is too alkaline, amending your soil with sulfur can help to adjust the pH level to make it more acidic and more conducive to healthy plant growth.