Add Sulfur to Your Lawn Sulfur is an important chemical. When we add sulfur to the lawn it converts into sulfuric acid. This acid reduces the alkalinity of the soil. You should hire skilled workers for this work. The best time to apply sulfur is Early spring or fall. Moderate temperatures promote the best results. Ammonium-Based Fertilizers Aluminium-based fertilizers are ... https://perfectgreenyard.com/lowering-ph-of-lawn/