The answer to 'why is my grass yellowing' is that there are several common causes, including nutrient deficiencies, drought stress, disease, or pest infestations. Yellowing grass is often a sign that the lawn is not getting the right balance of nutrients, moisture, or is being affected by environmental factors or pests.
Some of the most common reasons for yellowing grass include lack of nitrogen, overwatering or underwatering, fungal diseases like brown patch or dollar spot, insect damage from grubs or chinch bugs, or soil compaction. Identifying the specific cause is important to determine the best solution.