How To Test pH In Your Soil

by Matt Gibson

As a gardener, why should you care about the pH balance of your soil? Well, the pH balance of your soil will let you know which plants you can grow with ease and which plants will be a struggle without amendments. Knowing your soil’s pH is the secret to knowing what nutrients will be in the soil to absorb into the roots of new plants. What does pH stand for? It stands for potential Hydrogen. Huh? A simpler explanation is that pH is the acid / alkaline balance and the number tells you if your soil is acidic or alkaline or neutral.

Certain plants will thrive in acidic soils (0 – 6.5 pH) while others only perform well if the soil is alkaline (7.5 – 14). The ideal pH for garden soil is in the neutral range (right around 7). Once you know your soil’s pH, you can take measures to fix it, or you can choose to grow only the varieties of plants that thrive in your soil type. To amend acidic soil, simply mix in limestone. To amend alkaline soil, add in organic materials such as composted leaves, pine needles, and peat moss.

The most accurate and reliable way to check the pH balance of your soil is to have it lab tested. Your local cooperative extension office can test your soil’s pH balance in their lab and report the results back to you. (Most often they do so affordably or sometimes free of charge). While sending soil samples off to the lab is by far the most accurate way to test the pH, it’s not always the most feasible way to go about your business, nor is it exciting to let someone else have all the fun when you can break out the lab coat and do it yourself.

This article will break down the different do-it-yourself soil testing methods and review the different testing kits available to gardeners. Read on to learn all you need to know about how to test your garden soil’s pH balance so that you can make amendments to your soil—or at least make an educated decision on whether or not to roll with what you have this growing season. If you don’t like what you find out, you can change your soil’s pH balance over time. Until then, there’s always container gardening.

Soil pH Testers

There are three different types of pH testing kits that you can buy at the store to conduct pH tests at home. With each of these testers, the method is pretty much the same. You’ll need to take some soil samples from different parts of your yard or garden area, mix them with water or the buffering solution that comes with the kit, and then test out the mixture to see where it ranks on the pH scale.

Colored Dyes: With the colored dye kits, you’ll simply mix your soil samples with water and then add in the appropriate dyes, and the color of the resulting mixture will tell you the pH level of your soil.

Electronic pH Meter: With the electronic pH meter kits, you mix the soil and water and put the sensor into the mixture to read the pH balance. Avoid electronic kits that instruct you to stick the sensor directly into your soil to get the reading. While this technique may seem quite convenient, there is no way to get an accurate reading from soil without using water.

pH Test Strips: Of the three over-the-counter options for purchase, the pH test strips are the least accurate way to test your soil’s pH. These tests are based on litmus paper, which is far too inaccurate to test your soil’s pH level with. These strips are much better than standard litmus paper, however, and should help you get a better understanding of what kind of soil you are dealing with. Simply dip the paper into the soil and water mixture to get a reading.

Two DIY Methods

There are a few at-home testing methods that you can try without purchasing a kit, but they do require gathering a few ingredients. The first method requires vinegar and baking soda.

Grab a few cups of soil from several different areas of your garden, and mix them together. Take two spoonfuls of the soil mixture and place them into separate containers. Add a half cup of vinegar to one of the containers. If it starts to fizz, then you have an alkaline based soil with a pH between 7 and 8. If it doesn’t fizz up, try adding a few ounces of water to the other container, and mix until you have a thin mud-like substance.

Next, add in a half a cup of baking soda. If the mixture fizzes at this point, then you have a slightly acidic soil with a pH that is most likely between 5 and 6. If your soil and water mixture doesn’t fizz at all, then you have a neutral soil—and you can thank the gardening gods for it, as you have the freedom to grow most any plant that you like and can make small amendments to push the soil in one direction or the other, depending on what you are planting.

The second DIY method that you can try requires a red cabbage, distilled water, and a saucepan. Put two cups of water into the saucepan, then cut up one cup of red cabbage, and toss the chopped cabbage into the water. Simmer for five minutes, and then remove from heat and allow the mixture to cool for 30 minutes. Strain off the resulting liquid, which will be a blue-purple hue. Add two teaspoons of garden soil to a few inches worth of cabbage water, stir, and wait 30 minutes. If the water is colored blue-green, your soil is alkaline. If the water is pink, your soil is acidic.

Talk to Other Gardeners in Your Area

Aside from sending your soil into a lab for testing, using some tried and true DIY methods, or purchasing the over-the-counter testing kits, there is another way to learn about the soil in your area. Talk to other gardeners who live nearby. If you have a few gardener friends who live in the same area as you, chances are they are working with the same type of soil that you are. Ask them some questions. Find out what kind of plants your neighbors have had success with and what plants they have struggled with. This data should give you a reference point to help decide whether the soil in your area is acidic, alkaline, or neutral, and what kind of plants are suited to the location.

What to Do If Your Soil Is Acidic

If your soil is acidic, you have a few different routes you can take. You can either take steps toward raising the pH level of your soil, or you can do a bit of research and figure out which plants require acidic soil to thrive and which are less suited to the task. You can also pick up some containers and make your own potting soil mix that is specifically formulated to work for the plants you have selected.

What to Do If Your Soil Is Alkaline

If you live in an area with alkaline soil, you have a few choices. Either take measures to lower the pH balance in your soil so that you can grow a wider array of plants, or do some research and find out which plants will thrive in your area and which will not. You can always grow in containers and make your own potting soil mix if you want to grow something that likes acidic-based soil and you have alkaline soil.

The Best Action Is No Action

Luckily for gardeners, most plants are adaptable to growing in soil that falls near the neutral range, and most of the soil in the world fits into that range. Some plants prefer acidic soil and some prefer alkaline, but most can adapt to whatever soil type they are provided, as long as it’s not too far on either end of the spectrum.