I picked up a cutting in Hawaii back in March. When I took it out of the bag (yes it was one of those airport gift shop purchases) I noticed the bottom appeared to have some rot. Using a fresh razor I cut it back 2 inches and let it heal for 2 weeks. After reading through all the posts here and around the web I made a 50:50 mix of potting soil and perilite, dipped the bottom in rooting hormone, and set it in a 20oz plastic cup with dozens of holes punched in it all around. Gave it a light watering from the bottom and set it on a sunny window sil (we're in New Jersey). 4 weeks later the tip started to swell. We're now 5 months since the cutting was placed in soil and the leave are developing nicely (1). Since leaves have appeared I water super lightly (once a month, soil is bone dry in a week after watering). However, I see no signs of roots(2). The bottom portion of the stem is developing wrinkles (3). I pulled on the stem and the soil around the stem came out with it, the soil below the stem stayed in the cup. The underside of the stem doesn't look good (4, rot?). Is there any salvaging this cutting? Thanks so much in advance for the help.

You will need to cut again, and let it callous again. That is not looking healthy.

How far down from leaves or up from bottom would you suggest I recut? Healing time 2 weeks then back in soil mix? Do you think I watered too much?

To root a plumeria needs bottom heat and nothing else.
Start cutting an inch off the bottom, and cut until you get clean wood. Clean your clippers between cuts.

Thanks again for the advice. Unfortunately I appear to have cooked it. I recut it and this time placed the cup it was in on a hot plate. The temperature probe read 35C which would be in the 90sF but something must have gone wrong. The leaves were falling off this morning and the stem was soft. Par-cooked plumeria anyone. Guess we'll have to go back to Hawaii on another honeymoon to grab some more.