For the guru's: do you think this bitter cold will kill off garden pests more than milder winters?
No. Most pests have evolved to survive bouts of cold weather. It is a myth that cold winter weather reduces the pest population. My experience has been the opposite---that a spring after a very cold winter has higher, not lower, pest populations.
I still feel that extreme cold weather although very miserable has some benefits and know many farmers that feel the same way. I think it helps with some disease issues. I see less the summer after an extended cold spell like this one. We were -12 this morning and 29 now. Seems like a heat wave. If your ground is bare and freezes several inches deep it will tend to eliminate some problems. If mulched heavy then not as much if at all. The problem with most of the pests I have trouble with is they come in on the SW winds from southern Texas and New Mexico. So the cold here has no effect on them. My personal experience here is I might see a slight reduction in pest trouble after an extreme cold spell in the winter. But not that much as I don't have a lot of pests that overwinter here. The ground here is froze deep and has cracks in it from freezing. We didn't have any snow cover either which allows it too really soak in deep. So pest wise I don't expect to notice much if any difference. Disease wise I feel I will. Again personal experience which is with temps considerably colder and for longer periods of time than most of you will ever have. I know that one KSU agronomist used to say after a cold winter you would see less disease and he felt less trouble with certain native pests. Again just one persons opinion. And in colder temps than even I experience here. I heard of -22 lows not that far from me this morning. Jay