The answer to 'why is my irrigation system invasive plants' is that your irrigation system may be providing the perfect conditions for invasive plants to thrive. Invasive plants can take advantage of the regular water supply and disturbed soil around your irrigation lines to spread quickly, crowding out desirable plants in your landscape.
Some common signs of invasive plants in an irrigation system include fast-growing weeds, plants popping up in unusual locations, and reduced performance or blockages in your irrigation lines. To address this issue, you'll need to take steps to identify and remove the invasive plants, as well as make adjustments to your irrigation system to discourage their future growth.