Wednesday, February 6, 2013

How to Do a Free DIY Soil Test

As I've begun to journey into the world of gardening, I keep hearing a lot about soil pH and how important it is. But, as I've stated before, time and money have prevented me from taking my dirt to the garden center or shipping it off somewhere. I know I should, but I don't.

Another big part of the problem is that I never have really understood to science behind soil pH or how it really affects me. But I'm learning and growing. Here's the basic idea: soil pH influences the availability of essential nutrients in your soil. explains it like this:
The pH scale has 14 units and is centered on 7, which is neutral. Levels below 7 are considered in the acidic or sour range; readings above 7 are alkaline or sweet. Soil nutrients are at their optimum availability in the range between 6 and 7. Most plants grow best in this range, although some type of plant growth can take place anywhere between 3.5 and 10.
So in general, we want our soil to be as close to neutral as possible. Once you determine your soil's pH level, you can amend your soil with various additives (like compost, lime, pine needles, seaweed, etc.) depending on the acid or alkalinity of your soil. On a sidenote, in south-central Texas, the soils tend to be more alkaline since we have less rainfall.

How to test your soil for pH levelsOn to the soil test. This DIY test takes less than 15 minutes and requires materials that you most likely already have on hand, thereby making this test FREE (woo hoo!).

  • 1/2 cup vinegar
  • 1/2 cup water
  • 1/2 cup baking soda
  • 2 containers (a jar or mug would work fine)
P.S. If you don't have vinegar and baking soda around your house, start doing it! They are useful for SO many things and incredibly cheap. That's another post.

Step 1: Scoop some dirt into each container.
Step 2: Pour 1/2 cup vinegar into the first container.

Step 3: If soil bubbles and fizzes (like mine did), your soil is alkaline. No need to proceed to the next step.

Step 4: If your soil did not react to the vinegar, add 1/2 cup of water to the other container of dirt. Then add 1/2 cup of baking soda. If the soil bubbles up and fizzes (mine didn't), your soil is acidic.

Now that you know the general pH of your soil, you are better equipped to make decisions and troubleshoot problems! Don't you feel smart?! I have to admit that I do.

From here, you most likely want to amend your soil to try and get it in that optimal "neutral" range. If your soil tests alkaline (again, most of you Texans probably will), you will want to add pine needles (road trip to Bastrop, anyone?), sulfur, organic matter like compost, or liquid seaweed. If your soil tests acidic, you can amend with lime (ground agricultural limestone) or wood ash.

Also, do your research. While most plants prefer that neutral pH, some prefer more alkaline or acidic soil. Blueberries, for example, prefer acidic soils to thrive, so depending on what you want to grow, you may not need to amend at all!

If you want to have a soil test done for more detailed results (always a good thing), here are some sources:


  1. I'm not really into gardening, but that was a great article! I wonder what other applications this testing method could have?

    Assuming that the soil's acidity or alkalinity washes into the water when you mix the two, simple pH testing strips would also work too right?

  2. thanks so much for sharing your tip!!!

  3. Thanks for the information. Great tip!

  4. Will this work on Hydrangeas in Tucson, AZ