No plant of mine has ever survived rot. but what you could do is cut the rot and start a plant. You could also take a branch and start rooting as a backup. I can't tell where u live. If up north , you don't hv much warm weather left which is necessary for successful rooting. If you live in warm area u r prob OK.

You also don't say size of plumie so cutting rotted root and starting over may not b practical if u hv a large, hard to maneuver plant .

I haven't had this problem, but if it were me, I would take the plumeria out of the pot and wash any dirt off the root ball. Then, using a clean knife (X-Acto or you could sterilize a pair of small scissors with isopropyl alcohol), I would carefully cut off any roots that looked obviously rotten - brown and mushy. When you have the plant out of the pot, gently make sure that the lowest part of the stem isn't soft or rotten. It will probably look brown, since it's been sitting in soil, and it might seem slightly softer if the soil has been wet, so check for really obvious mushy spots. I would then repot in very well-draining mix, and put the plant in filtered sun. I would wait to water for a week or so, and when I did water, I would add hydrogen peroxide to the water. This post by Al explains the right concentration of H2O2 to use for the amount of water.

http://forums2.gardenweb.com/forums/load/contain/msg041148327553.html

You can just use the 3% hydrogen peroxide that they carry at the drugstore in the first aid aisle, and mix that in with the water you use for your plants. Hydrogen peroxide helps aerate the roots, and will actively prevent root rot.

After you repot, keep an eye on the plant. It will probably act stressed, but should recover. Keep it in filtered sun, and try and leave it alone.

It sounds to me like you might be having a problem with too-wet soil, which either means your soil mix is too heavy, your pots don't drain well, or that you're watering too often. You never want plumeria roots to sit in soggy soil. What soil mix are you planting in? How often do you water? What pots are your plants in?

If the lowest part of the stem is rotten, you'll have to cut off the bottom part and re-root.

I would also start with drying out the soil. If the stem actually has rot then cut, remove leaves, callus, and re root. If just the roots are brown then treat like you are rooting it again. A warm limited sunlight area on warm concrete would be my first choice for location.

My 7" plumeria cutting has been in a pot (2/3 perlite, 1/3 cactus mix) for several months. It has nice leaves forming, but it has not rooted. Today it got tipped over, fell out of the pot, and I noticed about 1-2 inches of root rot at the bottom. Is it a good idea to cut, dip in rooting hormone/ fungicide, and repot the cutting while its got leaves on it? HELP GREATLY APPRECIATED :)

I have something possibly similar going on with a larger tree I just bought. I have since repoted it, but I noticed it had no roots. I was thinking this might have been a very large cutting that hasn't rooted yet, but now I also have other concerns. It's probably worth noting that it has many small leaves and is flowing well. I wouldn't be concerned if I didn't know what it was missing down under.

Is this just a large cutting that hasn't rooted yet? Seemingly no sign of roots left behind when I repotted. I'm also going to try to talk to the nursery.

I also have a plumeria that looks like maybe it is rotten :( I don't know really what to do other than change the soil and put it in a different pot and cut whatever is rotten. But to be honest I don't know much about what to do at this stage. Maybe I overwatered her but I live in Los Angeles where we have great warm climate and I believe she can be rehabilitated back to her beautiful self. Can someone please help me and give me some advise on what to do.I would really appreciate it.

Hi Jenn,

use needle test. poke the needle into the branch close to the dirt and see if white sap coming out or not. If it does which means not rotting.

Ok thank u very much. Will do this afternoon and post pics of what I see.