No, baking soda lower pH soil is a common myth that trips up many gardeners. Baking soda is alkaline with a pH around 9.0 which means it raises your soil pH rather than lowering it. If you want more acidic soil for plants like blueberries, you need the opposite of baking soda.
I hear this question a lot from gardeners who mix up two different uses of baking soda. The home test for soil acidity uses baking soda to detect acid in your dirt. If your soil fizzes with baking soda, that means the soil is acidic. But this test has nothing to do with how baking soda soil pH effects work when you add it to your garden.
The confusion makes sense once you think about it. In the test, baking soda reacts with acidic soil and creates fizz. So many people assume baking soda must make things less acidic over time. But the reaction works the other way around. The baking soda is the alkaline part that causes the bubbles when it meets acid.
I made this mistake myself when I first started gardening. I had acidic soil at pH 5.5 and thought baking soda would help my tomatoes. Instead it pushed my pH up toward 7.0 in that spot. The sodium in the baking soda also made my clay soil crust over after a few months.
Some gardeners use baking soda to raise soil pH naturally when they have very acidic dirt. This can work for a quick bump but creates problems over time. Baking soda adds sodium to your soil. Too much sodium hurts soil structure and builds up to toxic levels for plants.
Elemental sulfur works best as a safe alkaline soil amendment choice for lowering pH. Soil bacteria turn the sulfur into acid over several months. This gives you a gentle drop in pH without the sodium buildup that comes with baking soda.
Your soil test results will tell you how much sulfur to add. Most labs list this info on your report. Follow their rates and retest in three to four months to see the change. Skip the baking soda myth and use the right tool for what you need.
Read the full article: Testing Soil pH: A Complete Guide for Gardeners
