I know it's a little early for me to be thinking about overwintering, but I have two giant (18 X 40) containers on my above-ground (5' approximately?) deck and I am planning to plant a clematis in each one. They both will be a 'Paul Farges' Summer Snow clematis which are hardy to zone 3 or zone 4 depending on which website you check. I am posting this because I have tried this before with two Henri clematis and they both died, but I don't think they are to blame. I'm just not sure how to take care of plants in pots over the winter. I won't be taking these containers inside because they are built into my deck and the vines will be gowing up a trellis that is also attached to the deck. I have been checking this forum and I see that I need to water the pots when they get dry, but I don't get it. Won't the water just freeze to a block of ice? Are you just watering when temperatures are above freezing? Are you watering every day? Every couple of weeks? When there is wet snow on the ground, are you still watering? And I have read that some people cover their plants so they don't get wet. These containers have drainage holes, will that suffice? Also, since these vines are supposedly hardy to zone 3, will I need to wrap my containers? I want to avoid that if possible because, well, the containers are pretty wooden boxes and that would look much nicer than burlap and newspaper. But I will wrap them if I have to, to keep them alive. And I am determined to keep these alive, so I would love to hear any advice you could give me.