Many plant cuttings will develop roots in water on a sunny window sill, even some woody plants. You might want to investigate some of the rooting systems that are being used now. Check out the propagation forum. There are instructions for building a small setup for minimal cost that virtually guarantees 100% success.

Last winter I set up a seed starting "mini'greenhouse" using a utility shelf, plastic drop cloth, grow lights and a home humidifier. For seed starting it was the most successful system I have ever had. I had it in the house, so the seed flats were warm enough after the seeds sprouted. For extra bottom heat I used a regular cheapo heating pad, which everyone says not to use, but it worked just fine and didn't cost $60 like the ones they sell specificially for seed starting.

The one caution I would offer is that I filled the utility shelf with seed flats. Then all the seeds spouted and I had to transplant many of them into larger pots before it was warm enough to set them out. But the shelves were full with the flats and I didn't have room for the larger pots, so they began to fill up the kitchen table, then the dining room table, then the kitchen counter tops and finally they covered most of the kitchen floor. So-o-o, remember that things may grow really fast under grow lights and be prepared for that. Cheryl

I started using my garage as a 'greenhouse' years ago, until we finally had to move the cars and bicycles out. Now I've finally got a real greenhouse (did my own share of lurking here), and this winter the car gets to go back in the garage. Like Cheryl says, it's remarkable how quickly it can run away with you.

I'm also zone 7, and I found that my attached garage stays warm enough to get most things through -- not always happy but alive. I used to monitor the temps and they were rarely as low as 40 degrees. Specific exceptions to what I could overwinter include coleus, which really didn't like the extended cool temps and some of the more tender aroids that don't want to go dormant. Bromeliads were touch and go except for dyckias/hechtias and tillandsias. If your cuttings haven't rooted yet you'll need bottom heat. I've used a small heating pad though I have a propagation mat now, and I've heard people say that waterbed heating pads work very well. Here in NC, humidity was never an issue, as the garage, being unheated, stayed much more humid than the house. It will be important to remember to keep things on the dry side during the cold weather so the roots don't rot.

Your million bells should overwinter OK in a garage under lights. They do for me even outside occasionally. I haven't tried the blue daze, and the only impatiens I've done in the garage is one of the hardier species (I. arguta) so it may not be reflective of what yours will do.

Good luck and if you kill something the first year, try again the next. I can't count how many times I tried with some plants before getting conditions right, but by the end of my 'greenhouse in the garage' phase it was amazing what I could pull off. -- Karen