Why Is It So Important to Test Your Soil's pH Level?

Maintaining healthy soil is essential to a thriving garden, which is why Tonya Barnett, the creator behind FRESHCUTKY Cut Flower & Vegetable Garden, says that detailed soil tests can make all the difference. These tests (which are often offered by local agriculture extension offices) give valuable insights into soil composition, provide growers with information regarding macro and micronutrients, and can direct specific amendments needed within the growing space. "While these more scientific soil tests are extremely useful, there are also a number of simpler ways in which growers can begin to better understand the properties of their own garden soil," she says. "One of the most important soil characteristics among these is soil pH." Here, she explains how to test your own soil's pH—and why this matters so much.

Related: How to Identify Your Garden's Soil Type

There are plenty of ways to quickly and easily test your soil's pH. An at-home testing kit or a digital soil pH meter are the most common, Barnett says. "These useful tools can usually be found at home improvement stores, as well as locally-owned nurseries and garden centers, at a very reasonable price," she explains. Believe it or not, you can also use food to estimate the pH of your garden's soil. "Dig into the garden soil at a level of about six to eight inches to collect a sample." Then, chop up some red cabbage and add it to a pot of distilled water. Bring the solution to a simmer until the water has turned a dark red. Once it has cooled, remove the cabbage and add some of your garden soil to the container. The water will either stay the same, turn dark blue or green, or turn pink. "This indicates whether the soil is neutral, alkaline, or acidic, respectively," notes Barnett.

Maintaining a proper soil pH is vital to growing a healthy garden. "Most plants prefer soils that are slightly acidic—however, there are exceptions," Barnett explains. Since soil's pH will have a direct impact on each plant's ability to uptake and utilize various nutrients within the garden, you'll want to make sure you know if you have a plant that prefers unique conditions—and then check to make sure that your dirt can meet its needs. "Conditions which are either too acidic or too alkaline may cause key elements in the soil to become unavailable to the plant," she continues. (The opposite can also be true. Certain nutrients may be freely used in excess, such as in the case of aluminum toxicity in plants.)

As for which plants prefer acidic soil? "Many edible and ornamental plants are considered acid-loving," Barnett says, which means their ideal pH levels should be slightly lower. "Without proper conditions, these plants may quickly begin to show signs of distress." Various types of evergreen trees, as well as many ornamental shrubs, will also fall into this category. "Most noteworthy of these plants are blueberries, rhododendrons, and certain types of hydrangeas," she says, noting that Hydrangea macrophylla, which is known for its large, color-shifting flower heads, is especially susceptible to changes in pH. "This intriguing characteristic is directly related to changes in soil pH," she says. "When the soil is alkaline, growers can expect pink flowers. Growth in more acidic soils will result in vibrant, true blue blooms."