The answer to 'why is my lawn yellowing' is that there are several common causes, including nutrient deficiencies, excessive moisture or drought, disease, or pest infestations. Yellowing grass can be a sign of an underlying problem that needs to be addressed.
Some of the most common causes of a yellowing lawn include a lack of nitrogen, which can cause the grass to lose its vibrant green color. Over-watering or poor drainage can also lead to yellowing, as can fungal diseases like brown patch or dollar spot. Insect pests like grubs or chinch bugs can also damage the grass, causing it to turn yellow.