I use a hardwood mulch in my beds----the perennials have been coming back 3 years now. I have silver mound, songbird cardinal columbine,red sage salvia, Purple Coneflower, hypernicum, Gaura lindheimen (karalee petite Pink) and Surprise Lillie bulbs planted in those beds, and they all seem to do great. My columbine has even managed to come back in 3 separate places. When it comes to annuals, I scrape away my mulch, plant what annuals I want & then push the mulch back onto place. Quick, easy & no weeds
But I should mention I put all of my perennials in as plants.