I did it a year ago. Yes, I just laid the stem lengthwise in one of those long, shallow planters. Put potting medium about halfway up on it. I put the side where there seemed to be the most "nubbies" under the soil. I could have divided them mid-summer if I would have wanted to, but I just left it. There was such a mass of roots when I cut them up yesterday; they were grown back and forth on the bottom of that planter. LOL Yes, I just cut the stem apart with a knife. Could use a bread knife (serrated) but like I said, I had one that I bought a long time ago that had a saw-type blade on the other side of the serrated part. Was advertised to be able to "cut frozen meat". Ya, right.........but it sure did saw through that stem without any trouble.
I realized I could grow more plants from those leafless stems a few years ago when I first cut one back. Threw the stem portion out on the compost pile (this was in May) because I had no use for it..........was gonna croak, right??? Mid-summer I went up to the g'house for something and when I walked by that piece of stem I gave it a kick to see if it was rotten..........it rolled over and the bottom was a mass of roots. Well, since it wanted to grow so bad, I put it in the long, shallow planter. The rest is history.
