Here is quote from Erv Evans, Consumer Horticulturist, NC State University from this site.
"Mulch can be applied any time of the year. However, the best time to mulch is late spring after the soil has warmed. Early spring application will delay soil warming and possibly plant growth. It is not necessary to remove the mulch when you fertilize. Apply the fertilizer over the mulch --- nutrients will move with water to the roots below. "