The answer to 'lawn fertilization not growing' is that there could be several common causes, including incorrect fertilizer application, soil compaction, improper mowing, or lack of water. Symptoms may include patchy, discolored, or slow-growing grass.
To troubleshoot, first check that you are using the right type and amount of fertilizer for your lawn. Apply it evenly and at the recommended time of year. Aerate the soil to address compaction, and make sure you are mowing at the proper height. Finally, ensure your lawn is getting enough water, especially during hot, dry periods.