Already planning for next year - anybody know about coleus?
I have a bed out front that is in deep shade. Hostas do fine there. Will coleus tolerate deep shade?
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Replant in soil in the spring and VOILA-- everlasting coleus!
I've done this for two years now with great success and have given cuttings to others that have grown well as well. 
they don't need a lot of water or space.
Don't worry if the cutting doesn't grow much and/or looks pathetic and shrunken by Spring. Rootings with just a few tiny leaves left on them have grown into big lush plants for me once they have a little time back in dirt.
to planting, so "many many months" would be my best guess.
The cuttings won't grow big leaves like they do in soil and the roots can get kind of dark (the sunshine hitting the water causes a green fungus to grow on the roots and in the jar). I rarely "change" the water and just top it off as needed. When the jars get really green'ish I'll wipe them out (a paper towel and a chopstick works great for this) and put in all fresh water, but it's more an aesthetic thing than a biological need.
My mother commented "I would have given up on this sad thing" when I gave her one of my rootings earlier this year, but it is a thriving bushy resident of her doorstep planter now.
Once re-planted, it can take two weeks or so to really get going again, but every rooting I've done this with eventually grows big and healthy.
I'm recharging my camera battery now, but will try and post some pics of my current rootings later.
For some reason, the green scum in the jars isn't showing up much, but I assure you, it's there! 
The green w/red center leaves cutting sticking out to the right in the left hand jar and the little red one in the middle are representative of what your cuttings will look like after many months in water. The bigger ones are cuttings I've already taken from this year's crop. They will lose their bigger leaves and make small ones to replace them.
(I took them off the window sill for the photo shoot b/c the light was really messing with getting a good shot of both the water and the plants.)
Happy rooting! Let me know how you do with it. 
I have an Angelonia plant that I grew from last year's rooted cuttings and this year I discovered catalina (wishbone flower) and marigolds will root in water. Remains to be seen if they will overwinter but it's always fun to try.
My craziest water survivor is a hosta cutting my mom gave me last year. All the leaves fell off but I kept the roots in water and they grew new leaves this summer. It's still sitting in the windowsill and may have to wait until next year to go in the ground b/c shady spots are few and far between around casa de beac.
