The answer to 'mulch has weeds' is that weeds can often grow in mulch due to weed seeds being present in the mulch or blowing in from nearby areas. Symptoms include seeing weeds poking up through the mulch layer. Common solutions include removing the weeds by hand, applying a pre-emergent herbicide to prevent new weeds from sprouting, or replacing the mulch entirely.
While some weed removal and mulch maintenance can be done DIY, it's best to call a professional landscaper if the weed problem is severe or you're unsure of the best treatment approach. Professionals have the right tools and expertise to effectively manage weeds in mulch without damaging your landscape.