The answer to 'why is my garden brown patches' is that there are several common causes, including drought, disease, pests, and improper lawn care. Brown patches can indicate problems like fungal infections, insect damage, or nutrient deficiencies in the soil.
Some key symptoms to look for include discolored, dying grass, mushrooms or other fungi growing, and visible insects or larvae. Solutions may involve adjusting your watering, mowing, and fertilization practices, as well as treating any diseases or pest infestations.