The answer to 'why is my mulch drainage problems' is that poor mulch drainage can be caused by several factors, including compacted soil, improper mulch depth, and lack of slope or drainage. Symptoms of poor mulch drainage include standing water, soggy soil, and slow plant growth.
To fix mulch drainage issues, you can start by aerating the soil to improve water infiltration. Ensure the mulch depth is 2-4 inches, and create a slight slope away from your home's foundation to allow water to flow away. If the problem persists, you may need to install additional drainage systems, such as French drains or catch basins, which is best done by a professional landscaper.