Question: “I have some native plant beds that were previously lawn and now have a pretty heavy layer of hardwood/shredded mulch (because I didn't realize I should be putting in groundcover plants). Should I work on removing the hardwood mulch? is it okay to leave it?”
Mulch can be a great way to get your native beds established, keeping weeds down in the first few years until they can be come established. This keeps moisture in the grown and can help eliminate the need to herbicide use by suppressing weeds.
However, we do recommend transitioning away from annual mulch use and moving towards “living much” by planting grasses and sedges in between flowers. This living mulch is natures way of keeping down the weeds and make for a more complete ecosystem and more natural structure.
I would not recommend removing the wood mulch, nature will break it down eventually. We would recommend that you plant enough native plants in between existing ones so that they can function as this living mulch. In time the living mulch will fill in and you will need to do less and less weeding.
I hope this answers your question.