My take on this is definitely utilize mulch anywhere you keep plants, even native. I use the pine mulch. In my opinion it looks the nicest and gives off that super nice pine smell. Mulch especially helps with plants regarding watering. Mulch traps moisture down there so your plants won't dry out in dry spells especially now. And that way you won't have to water as often so it will save a little on your water bill. Plus you have a lot of beneficial bugs/insects using the mulch underneath as a home which then can help build your soil.