That is interesting, Vickie. I do everything possible not to have my cuttings touch any water, at least not at the cut-end and certainly not any moisture that will be prolonged. You are rooting yours the opposite way that I do. It will be more than interesting to see how your plant roots as we go along. You need to update the progress with words as well as pictures. I selfishly want you to continue to keep it (rooting) in water rather than move it to soil or some other growing media.
Your zone, though much colder than mine, is still no different than what I have to do in the fall...........bring all my plumeria inside. You would just have to do this sooner than I and it would be later bringing your plant back outside in the spring. Dormancy is dormancy. Do you have a sunroom, a large window with lots of bright light, or perhaps a greenhouse, so that the plumeria will have an extended growing time? You only have the single plant so overwintering it will be a piece of cake.
By the way, simply because these are trees (and I don't know whether you have a standard or a compact grower), you can easily keep the tree about any size you wish. Just like you started with a small cutting, you would simply take cuttings to keep control of its size. Do you happen to have a variety label that came with your plant?
