I have a couple of pomegranate bushes here in the Portland area. Last winter there was pretty severe die back on both in winter. Luckily they came back from the root or from the "trunk". This year after they lost all their leaves, I covered them with a bucket and big black pot after pruning back the tips so that they do not touch the plastic.
Is this likely to succeed for winter protection or am I better off without it?

Having a black pot over your plant might not be a good idea if it is in full sun. Could get very warm inside the pot and break dormancy during the day then freeze at night. Might be better to cover with a light colored pot instead. Should also allow some ventilation.

Mine also died back last year, but came back from the roots. When it's really cold, one doesn't have to worry about rain making things wet and soggy/heavy. I tend to go more with tarp or fabric options. I also think that good drainage will do a lot for the subtropical plants here in the winter.
John S
PDX OR

John, I don't understand why, can you explain more?

More plants die in the winter from diseases that they get here when they get waterlogged and aren't able to defend themselves. This is especially true of plants from dry areas, like pomegranate, that have developed no natural resistance to them because they don't need to. The wet side of the NW isn't that cold, so few plants actually freeze to death.
John S.
PDX OR

(shrug) I bring my pomegranates indoors for the winter.