Is testing the pH of soil with cabbage juice accurate?

Question

I was looking into testing the soil in my yard so I knew how much I needed to prepare it for blueberry plants. I came across a method I hadn't heard of before, that I thought was interesting.

It involved boiling cabbage leaves in distilled water, then placing the soil in the juice. Then supposedly the juice will change colors based on the soil's pH level.

It sounds pretty easy, but I was wondering if that's an accurate method for testing the pH of soil? Is it accurate enough for a general idea of where the pH is at, or should I not use that method at all?

Answer 1

It will tell you whether your soil is above or below a pH of 7.0, turning green or red, respectively. It will not tell you the exact number, which is why a real test is required. Anthocyanin is the coloring agent in red cabbage, and turns red at a pH of less than 7.0. The best way to test your soil is to either buy a test kit, or digital meter, or if you don't have much time, like me, and want a complete soil profile, send some soil to a lab (I use my county extension agency).

Here is a good article on the subject of anthocyanin and pH.

Answer 2

Maybe not an answer,but; Bromthymol blue works well . It is available in any pet shop to test aquarium water. Put a soil sample in distilled / rain water, etc , shake it , let settle and withdraw a sample. To acidify the soil, I found conc. sulfuric acid worked well, poured about a foot from the blueberry plant ( 500 ml/plant.). Gypsum ,etc didn't work for my soil.