Mechele, in your Zone I think it would be fine to plant out hardy perennials in your garden now. I am often in your situation and have planted out perennials as late as October 26 (according to my journal) with success. However, if for any reason I can't plant out, I sink the pots/WS containers in the ground over winter and then plant out next spring. That works well for second year flowering perennials - you get flowers the first year they are in the ground. Don't forget the earth is still pretty warm.

If they were my plants, I would sink the pots in the ground and leave them alone until you are ready to plant them in the ground in their permanent positions next year. Clematis take time to get established any time they are planted and removing them from their pots, planting them temporarily in the ground, and them digging them up once again to put them in their permanent position is going to put them back twice. Another advantage to leaving them in their current pots and burying them in the soil is that most plants put on the most root growth in the fall as the air and soil temperatures begin cooling down. Allowing your clematis to sit in their pots over the fall and winter and into next spring will allow the plants' root balls to get larger and thereby increase their take off once planted next spring. The soil will act as an insulator and any mulch that you add with further insulate the roots allowing them to continue growing much longer into the fall and winter. Realize that root growth will continue some time after the top portion of the plants has been nipped back by frost. Another point to consider is that it is generally advised to plant clematis in the fall in the ground so that they have a minimum of 6 weeks to get settled in before the colder weather arrives. I see you are in zone 5 and don't know exactly when colder weather arrives so to be on the safe side, I would be hesitant to remove the plants and plant them in the ground in your garden now. As to your browned out leaves--that could be due to the plant not being watered adequately and it allowing the top portions of leaves to die off so that the plant has less leaves to lose water from via transpiration, it could be the plants response to being in a black pot sitting in the full sun at the nursery, or depending on the variety, it could possibly be clematis wilt. I would be tempted to leave the plant as it is, water it well, put the whole pot into the ground, mulch it well, and keep it watered if Mother Nature is not being cooperative. Next year, when you are ready to plant the clematis in the garden, I would cut the top growth back so that you have two or three nodes left above ground once planted, fertilize it with some slow release low nitrogen fertilizer, and see what happens.

JPW, I personally don't like to attempt to overwinter clematis inside the house for the reasons you mentioned with roses above along with the fact that the plants tend to get very leggy unless you have a window that gets lots of direct sunshine. You said that last year when you attempted to overwinter them outside, that all except one died. How big are the pots your clematis are in? How did you attempt to overwinter them outside last year? Did you cluster the pots together in a sheltered location? Did you leave them sitting out in the open where they were exposed to the elements? You could attempt to cluster them together and place some sort of insulating material around the pots such as bales of straw or the like. Even if you had an unheated area where you could store the pots after they had been exposed to sub-freezing temps that took them into dormancy, that would be better as far as I am concerned than attempting to bring them inside the house. Do you have friends with uninsulated garages or even crawlspaces that could store the plants for you?

You didn't say if you've been growing them indoors or outside. I like to take advantage of the summer months and leave my seedlings outside all summer in partial sun/shade so they build roots and photosynthesize, all the way into late Fall when cool nights and diminished sun exposure causes the seedlings to go dormant. Next, place them somewhere that stays cool enough so the stay dormant (35f-45f degrees). You want to be able to check on them so they don't dry out and secure enough so varmints can't prune them off for you. I've never grown in zone 6 so I assume it's a lot easier than zone 3 where I live.