I don't think the mulch caused any problems. It does a great job of keeping soils moist. Some situations do better with a thin layer of mulch and others do best with thick layers many inches thick. And places way up north can have problems of the mulch keeping the soil frozen long into spring, but we don't have that issue down here.

Your perennials might have been eaten by voles over the winter. Voles live under the mulch and will eat anything.

It does also depend on what kind of perennials they are. Salvias, for instance, like it quite dry and the ones I lose are the ones heavily mulched.
If they haven't come up by now they are gone.
Do you know what any of them are?

Perhaps, if you buried the crowns of the plants too deeply.

I never use heavy mulch or any kind of pre-emergents, etc. because many of your "perennials" are self-seeders. Heavy mulch will suffocate the seeds or plants with delicate, shallow root systems. That's what I think happened.

Don't despair though, you have wonderful beds already created for you to just add more plants. If you are in the Raleigh area, the gardenweb fall swap would be a good place to start.

When I moved here to Sanford 12 years ago, although the property was beautifully landscaped, there was not a single perennial of any kind here and no beds dug in this heavy clay. I've had a shovel in my hand every since...including today in the heat. Press on, all is not lost. Only the fun part remains for you.

claire in sanford