Last year we purchased a truck load of wood chips to winter mulch our plants. Someplace here I believe I read about not using fresh wood chips because of the nitrogen (or something). I really piled it on our hydrangeas for over the winter and this summer one died and the others didn't bloom. I know we had a spring frost that I was blaming but in the back of my head, I remembed reading something. Opinions please beforre we use the rest of it this year..
"fresh" mulch
Probably what you had read is that fresh wood chips can deplete some nitrogen from the soil as they decompose, but I doubt that could kill a plant--at worst you'd notice some slower growth or something in the spring, but if you fertilized in the spring then you likely wouldn't see any effect at all. In your zone a spring frost will almost definitely kill off your buds if you've removed the winter protection already, so that could definitely explain why you didn't get any blooms. Since you're near the lake and a little warmer than some parts of MI I wouldn't think the cold would completely kill the plant, usually I would think they'd come back with new shoots from the base, but again the cold is a more likely suspect than the wood chips.
Wood chips have the problem that they host shotgun fungus which will permanently stain fences and houses but they are good mulch to use nonetheless... as long as the wood chips are not from black walnut, butternut or ailanthus wood (those are toxic to many plants).
This thread has some info on fresh wood chips as mulch and also on the effect of balck walnut wood chips
http://davesgarden.com/community/forums/t/901740/