The answer to 'why is my sprinkler system overgrown' is that your sprinkler heads may be obstructed by overgrown vegetation, causing poor water coverage and allowing weeds and grass to grow around the sprinkler. This is a common issue that can happen over time as plants and shrubs expand around the sprinklers.
Some common symptoms of an overgrown sprinkler system include patchy, uneven lawn coverage, areas that remain dry even after watering, and weeds or tall grass growing directly around the sprinkler heads. The solution is to regularly inspect and trim back any vegetation that is blocking the sprinkler heads so they can properly distribute water across your lawn and landscaping.