O, that is so sad! I hope you don't lose them too, but your description doesn't sound good. The plastic bags kept them too wet. They couldn't breathe. I've not had much luck with those like that. It was a hard lesson, but good luck,
Steve.

No it doesn't sound good. You could cut a little off the end of the cane. If it is white colored your ok, if it's brown cut back further.

The roses have to go dormant first, no green leaves, before being brought into the garage.
Spray them with a fungus spray that's effective on Powdery Mildew. They should be exposed to a good hard freeze before being brought into the garage and the garage should not be heated.
My potted roses are placed in an unheated greenhouse where they get light during the day. The soil in the pots freezes during extremely cold spells. They get just enough water to keep them from drying out. Come spring they all leaf out and do well.
Over protecting can be worse than under protecting.

Crap!

Yes, now in retrospect, I've done it all wrong!! Which is strange since I have overwintered roses in the garage at my old house. I just did it all wrong this time.

PLUS - our garage's heater kept going on all night to keep the temperature warm. I noticed it one morning!!! GAH!!!

And you're right, Karl, the leaves were still sort of green.

Oh well, I guess this was an expensive lesson. :(
I'm bummed!

Carol

Need not be. They're not dead until they're dead. Spray to kill the mildew or, this late in the season, strip the diseased leaves off and spray the mildewed canes. After making sure they're dormant and the heater is off for the winter, bring them into the garage. Care for them as needed during the winter and see what's alive come spring.
I suspect most will survive.

Karl's advice sounds very right on. I would spray and strip off the foliage and prune back any black/dead cane and stems that are still there.
Let them go dormant and don't cover them up.
I overwinter all my Pot Ghetto in the unheated garage here in Northwest Missouri zone 5b/6a uncovered. I give them a drink if they get dry or put a shovel full of snow on top of them and let that slowly melt into the container. That seems to be the best way to keep them hydrated during the winter. You definitely don't want them to dry completely out even if they are dormant.
John

Okay Karl and John. Here's the thing, I've never sprayed anything - there's no need here. So what would I spray? I wonder if anyone sells anything for mildew at this time of year. Wait, I know that all the greenhouses are open selling Christmas stuff. I'll go check it out. Thanks!!

You give me hope!!

Carol

How can you tell when the pot is drying out? How much water would you give to an one gallon pot?

During winter, a shovel full of snow in the pot will supply enough moisture as it melts to sustain it. I stick my finger into the soil. If it feels moist it's OK, if dry, I add a cup full or so. You just want to add enough to keep the rose from drying out. The soil should be moist not wet.