This post is sponsored by Stonyfield Kids.
Here’s something super fun — and practical! and science-y! — that you can do with your kids this weekend, or maybe over summer break. Did you know you can test the PH of your soil right at home? It’s true. And all you need is distilled water and red cabbage.
It’s called the Red Cabbage Soil Test and I learned all about it from the team at Stonyfield, when we were talking about their StonyFIELDS initiative — which is focused on stopping the use of harmful pesticides on all playing fields.
Their goal is to help communities across America take the necessary steps to convert to organic field maintenance, and there are towns across the country that Stonyfield is supporting as they transition their playing fields and parks to pesticide-free care. As part of that support, they teach interested citizens how to test the soil in their own gardens, or on any field or lawn they interact with, using the Red Cabbage Soil Test.
If you want a more official soil report, you can send a dirt sample to your local university, and they’ll test it for you. But the Red Cabbage Soil Test is a great way to make a simple baseline assessment. And it’s really enjoyable too.
Step 1: Shred approximately one third of a head of red cabbage.
Step 2: Boil cabbage in one quart of distilled water. It has to be distilled, because distilled water has a neutral PH. Once you get it to a rolling boil, simmer the cabbage for five minutes.
Step 3: While the cabbage boils, gather a few more supplies — a few glass jars (we ended up using five), some white vinegar, a box of baking soda, soil samples from your yard (or the park!), and snacks of course.
For our experiment, Oscar gathered soil from our upper yard and lower yard.
Step 4: After the five minutes of simmering, strain out the cabbage and put the boiled water in glass jars — it will be purple!
If you only have one soil sample, then technically, you really only need one jar, but the first time you try this, it’s fun to fill several jars to make it more of an experiment. I’d recommend splitting up the purple water among five or six jars.
While the boiled water cools down, enjoy a little snack break. : ) We recommend Stonyfield Tubes in Cherry/Berry. They’re portable, easy, and delicious. Oscar and Betty favor them frozen — and it makes them keep better in lunch boxes too! We also love the new Whole Milk Tubes in Strawberry Beet Berry.
Step 5: Once the purple water has cooled, add a little bit of white vinegar to one of the jars. No need to measure, just pour in a bit and see what happens. Your kids will be delighted to see the water turn bright pink!
Step 6: To another jar of purple water, add a little bit of baking soda — a few pinches is plenty. This time the water will turn blue!
Now, you’ll have three colored water samples — blue (basic), purple (neutral), and pink (acidic). You’ll use these as color references when you test your soil.
On future tests, you don’t need to do the baking soda or vinegar — you can just remember what each color means — but I think it’s fun the first time.
Step 7: Add a little soil from your yard or garden to one of the purple water jars.
Wait a few minutes and then look at the color of the water. If the soil is already PH neutral, the water will stay purple. If the soil is acidic, the water will turn pink. If the water turns blue, the soil is basic.
Once you test the soil, if you discover that it’s too acidic or too basic, you can “correct” it. For acidic, you could add lime or wood ash to raise the PH and get it closer to neutral. For basic, you could add compost to lower the PH.
We tested two soil samples from two different areas. One stayed pretty purple, so we determined it was PH neutral. The other one turned reddish/pink, so we knew it was acidic. Pretty cool, right?
If you’re curious to learn more, here’s a video with additional details about the Red Cabbage Soil Test and other ways to keep your playing fields safe and thriving.
Your turn! Have you ever tested your soil? Do you already know if it tends to run more acidic or more basic? Have you ever tried to alter it in an attempt to help a particular plant thrive? Have you ever gathered soil from your playing fields or parks to get tested (or to test yourself)? I’d love to hear!