The answer to 'why is my lawn overgrown' is that your lawn is likely overgrown due to a combination of factors such as infrequent mowing, excessive rainfall, or lack of proper lawn care. Overgrown lawns can be caused by letting the grass grow too long between mowings, which can lead to an uneven, shaggy appearance and make it more difficult to maintain.
In addition, periods of heavy rainfall or mild temperatures can cause the grass to grow more quickly than usual, leading to an overgrown lawn. Neglecting other essential lawn care tasks like fertilizing, aerating, or overseeding can also contribute to an overgrown lawn over time.