14 Ways to Use Baking Soda in the Garden June 1, 2016 PrevNext Use baking soda to test the PH level in your soil. Wet your soil with some distilled water and then sprinkle baking soda on top of it. If the baking soda bubbles, you have acidic soil with a PH level that is probably lower than 5 (7 in neutral). PrevNext