Yes, the wood chip mulch was something we thought about, but have been steered away from in the orchard for voles exactly as you predicted.

That’s a great idea to use with in rhubarb, we’ve been using straw in ours. I’ve often heard that wood chips can “tie up” nitrogen, leading to a deficiency in the crop, but I don’t understand the science behind it, and whether or not it would have that negative effect on rhubarb. Thanks for the idea!