Is there a reason you wait to lay down your mulch? I guess it depends, if it is a vegetable garden you are trying to warm up, then you want to wait. If it's a perennial garden that has plants still coming up that you don't want to mulch over, then wait. If it is a shrub border, then I don't see the advantage for waiting.

I'm in the Portland Maine area and I plan on mulching my perennial beds next week or week after, depending on time and weather. I personally like to give the soil in my beds a chance to thaw and warm up before putting any down. I prefer not to mulch until after the middle of May.

Combination of perennial beds and shrubs. But since we get a truck delivery we do it all at once.

hmm I've mulched potatoes(i'll be a weeding in June), strawberries, herbs, onions, cold weather greens, and even soybeans I sowed along with peas from late march....think that does it but it's never to early to mulch(straw).

I mulch whenever I have time and the mulch is available.