Answer: It's fine to mulch your beds now, in mid-November. The concern with mulching much earlier than this is that a spell of warm, wet weather might cause the crowns of mulched plants to rot. But now that the weather is, for the most part, consistently cold, go ahead and cover with spruce boughs.
Another concern with mulching too early--say, in October--is that by insulating the soil it will stay warmer, and the plant may delay entering dormancy. Again, by now plants should have stopped growing, so it's fine to mulch.
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