The answer to 'why is my mulch weeds' is that weed growth in mulch is a common problem caused by a few key factors. Mulch can provide a fertile environment for weed seeds to germinate and thrive if not properly maintained. Factors like insufficient mulch depth, poor weed control prior to mulching, and decomposition of the mulch material over time can all contribute to weed growth.
To prevent and address weed issues in your mulch, it's important to start with a thick, 2-4 inch layer of high-quality mulch material. You'll also want to ensure you remove any existing weeds and their roots before applying the mulch. Regular maintenance, like raking and replenishing the mulch as it decomposes, is key to keeping weeds at bay. If the problem persists, you may need to consider more intensive weed control methods or even consulting a professional landscaper for guidance.