That's what I was describing above, leaving them in water. Guess I wasn't so clear, sorry. I don't do anything with soil for Coleus cuttings inside (or Perilla.) Not against it, there's just no room here. No risk of overwatering. I've done it for over 20 years, so it's not an issue of wondering if it works. Put the bottles in windowsills, any but north seems to work well, make sure they don't dry out, no foliage under water because it will just rot. Change water if something falls in there and grows mold before you notice to get it out, if there's any color or odor. Not advocating one or the other, just relating what I do and why. I think it's very cool Coleus can be saved in so many ways in so many places, and love to hear about them all. If something doesn't work, there's other options to try. Not everybody has old-school windowsills 7" wide, so this (just water) might not work as well.
I really waited until the last minute last fall and the results were not as good as in previous years. The % of pieces that failed to take root was avoidably high (if they match my theory, which is that it was because it had been hovering around 40-45 at night for a couple weeks before cuttings were finally taken on panic night) so I won't be waiting to do it like that again. Correctly pegged the first night of frost, but the plants were already stressed and weakened. Some things can grow back from the roots after a winter of frosts, but not Coleus. One overnight frost is often enough for a complete kill shot. They're utterly tropical plants not built to deal with seasons or temp fluctuations besides day/night at all. I believe that if I had taken cuttings when the temps started to dip so low at night, I would have had much more plant material to use this spring. It's not about the date, just the weather.
We didn't have to close the blinds after a few weeks of bringing the cuttings in last winter, in the room where tv and computer are because there was so much foliage blocking the view in, except up high on the walls. A little more tricky in bedroom windows but after a couple weeks, all of the leaves turn and lean toward the window, so the delicate operation of trying to open/close drapes/blinds behind plants is short-lived.
