The answer to 'why is my mulch invasive plants' is that certain types of mulch can harbor and spread invasive plant species. Organic mulches like wood chips or bark can contain seeds, roots, or fragments of invasive plants that then take root in your landscaping. This can lead to the rapid spread of weeds, vines, and other undesirable plants that outcompete your desired vegetation.
To prevent this, it's important to use high-quality, weed-free mulch from a reputable supplier. Opt for mulches made from shredded hardwood, pine bark, or other non-organic materials that are less likely to contain invasive plant matter. Regularly maintain your mulch by removing any weeds or unwanted growth that emerges, and replenish the mulch layer as needed to keep it 2-4 inches deep.