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How to Check Your Soil's pH Without Purchasing a Soil Testing Kit

Lockridge is an avid reader who enjoys learning about beautiful garden plants. Among other things, she has worked with a florist.

Don't just assume your plants will grow well in your garden soil. You may have to add soil amendments.

Don't just assume your plants will grow well in your garden soil. You may have to add soil amendments.

Not all plants are alike. Some like soil that is more acidic, whereas others like soil that has a higher alkali content. If you already have a type of plant in mind, you may have to add a soil amendment to make your plant thrive. If the soil balance of nutrients isn’t right for your plant, it just won’t grow to its potential.

Blueberries, beans, broccoli, kale, peas, and onions prefer acidic soil, whereas cabbage, cantaloupe, turnips, and leafy greens prefer alkaline soil. Generally speaking, most fruits and veggies prefer neutral soil, though.

Instead of buying a kit at the home-and-garden store or sending off a soil sample to a testing center, you can do a few basic soil tests at home without much cost involved.

Soil Preparation Instructions

In order to get accurate results, it’s best if you get an accurate sample of your soil.

  1. Remove any non-organic debris (such as rocks) and break up large clumps of soil.
  2. Dig several holes 4–6 inches deep in the area you want to plant. Gather samples with a cleaned garden tool.
  3. Combine soil from different holes together and mix well. Remove any remaining sticks, stones, or other foreign matter in your soil.

The Cabbage Juice Test

  1. Add 2 cups of distilled water to a clean saucepan.
  2. Add 1 cup of diced red cabbage to the water.
  3. Simmer for about 5 minutes.
  4. Remove pan from heat, and allow the mixture to cool down for approximately 30 minutes.
  5. Strain liquid from the diced cabbage and set aside into a bowl. The cabbage juice should be bluish/purple color.
  6. Pour about ½ of the mix into a separate bowl.
  7. Add about 2 teaspoons of garden soil to the jar, and stir thoroughly. Look for any changes in the color of the water; it may take 30 minutes. If the liquid turns bluish/green the soil is alkaline, if the liquid turns pink your soil is acidic.

The Vinegar and Baking Soda Tests

The Alkalinity Test (Vinegar)

  1. Place about 1 cup of soil into a clean jar.
  2. Add enough distilled water to the jar until the soil turns muddy.
  3. Add ½ cup vinegar, stir gently, and observe mud for any changes. If the soil starts to fizz or foam the soil is alkaline. If you don’t observe any changes, continue the test for acidity.

The Acidity Test (Baking Soda)

  1. Place about 1 cup of soil into a clean jar.
  2. Add enough distilled water to the jar until the soil turns muddy.
  3. Add ½ cup of baking soda to the mud, stir gently, and observe mud for any changes. If the soil starts to fizz or foam the soil is acidic.
  4. If your soil didn’t fizz and foam with any of the testing, your soil is likely neutral.

The vinegar and baking soda test won’t give you an exact pH level of your soil, but it will tell you if the soil is leaning acidic or alkaline. For an exact pH range, you would need to purchase a pH soil testing kit or send it off to a local cooperative extension for evaluation.

How to Amend Your Soil

Based upon your soil test results, and what you plan to plant, you may need to add something to the soil to make it more hospitable. Generally speaking, a more accurate test (that give you an actual pH number) will give you a better idea of how much and what types of amendments you’ll need to add to your soil.

The most common soil amendments include:

  • Builder’s Sand—improves soil drainage
  • Clay—used for water retention, allows water to reach plant roots
  • Fertilizers (such as compost, manure, or peat)—used to add nutrients to the soil
  • Gypsum—improves soil structure and releases nutrients into the soil
  • Humus—decayed organic matter used to improve moisture retention and aeration
  • Lime—used to make soil less acidic
  • Perlite—Improves aeration and drainage
  • Vermiculite—aids drainage and aeration
Notice the clumps of organic matter in the soil.

Notice the clumps of organic matter in the soil.

Another Helpful Resource

The Spruce: Four Easy Do-It-Yourself Soil Tests

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2018 Diane Lockridge