How can I measure the pH of my soil?

Question

I was told to measure the pH of my soil to help identify some of the symptoms on my vegetable plants. Does anyone have recommendations of a device I can purchase to measure soil pH?

Answer 1

The best way is to get a soil test. If you can find a COOPERATIVE EXTENSION SERVICE via the closest University, it is cheap and possibly free. Otherwise there are cheap tests like the ones used for HOT TUBS. There are also these pronged things that seem to work well. I own a very expensive pH tester and test these other cheap LOWES or HOME DEPOT pH testers. They have impressed me. I always use at least two forms of testers. Need to have moist soil and test multiple places. Potatoes, blueberries need acidic soil; 5.0 to 5.9. Other plants need more alkaline soil; 6.0-7.3.

pH is one of the best ways to separate real gardeners from wannabees! With this knowledge you can plant alkaline loving plants together and the acid loving plants together. To plant any acid loving plants next to concrete you will find is nuts. But one CAN change the pH of soils, slightly. Harder to make soils more acidic. Always do in stages, test again, add lime for alkaline (going up on the scale) and add sulfur (going down the scale towards acid)...go SLOWLY. Takes weeks to months to see change. Keep this in mind when you test.

Answer 2

Measuring the pH of soil is cheap and super easy (I do this often).

1. Get a (plastic) bowl.
2. Put a sample of soil in it.
3. Add distilled (not rain or tap) water and mix it to the consistency of a milk shake.
4. Wait 30-60 minutes, until the soil settles and you have mostly water on top.
5. Test the pH of the water/supernatant with a pH meter or litmus strip(s).

Trouble shooting tip: If you added too much water, add more soil.

Question: How do I know this is accurate?

Answer: pH is logarithmic, so you can't go very wrong. In other words if you have a 100 ml of solution with pH of 6.60, and you add 100 ml of distilled water to that, the pH of the 200 ml solution will be 6.71. So, being off by less than double the amount of water will not mess up your results too much.

Question: why do I have to use distilled water?

Answer: The pH of rain water is about 5.6, and the pH of tap water should be between 6.5 and 9.5... and it often is.

Question: Where do I get litmus strips or a pH meter?

Answer: Online (like eBay) will work; or the pharmacy, aquarium, pool, or lawn and garden section of many box stores (like walmart) should also carry them. There are (probably) thousands of pH strip products... they will all work for soil testing.

Shopping tips: For testing soil, any cheap pH strip (within range) should be good enough; look for strips that have good color definition around pH 5 - 9. Pool pH strips might be more expensive and specific for the higher range (pH 7 - 10) and they might include other/unnecessary tests. On the other hand, if you have a pool, then having dual purpose strips makes sense. Otherwise, I would probably opt for something like urine or aquarium strips (which are usually meant to read pH in the range of 4 to 10).

For pH meters, look for a model with straightforward calibration techniques. Always check the product reviews before spending your grocery money.