Go buy a common garden fungicide (ie.Schultz). 1. cut mushy back to all green, let it dry an hour. spray with the fungicide. I then cover it with common household spackle to seal and make it look better. It will seal itself, but the spackle cuts down on cracking, new fungus, and looks clean. 2. This probably will not affect the plant, but I cannot see where the leaves are coming from. I would do the same as in #1 and leave the leaves if you can trim around. 3. Leave it. No mushy no problem, yet. Spray the tip and watch it. Some tips are slower to get started after frosts. 4. Spray the black and watch it. As long as it stays hard, the new growth will channel the energy and the hard black knob will just look black. You can trim it off with an exacto knife but I just let them go. I live in So,Cal and with light winter frost, then sping fog then rain, I have a battle with black tip every spring. Once it heats up, the problem is gone. But if you do not treat mushy stems they can kill the entire plant. Your plant look generally healthy, so spray the black tips after rain or if it gets wet. Also, on #1 make cuts at an angle so water does not sit on the cut. I cannot see how deep that hole is but this is the one to watch, the others should be ok.

For future reference, a blanket or a sheet is not a good cover. These become wet and then freeze onto the plant, If you hunt around in farm supply shops you should be able to find some commercial frost cloth which is not expensive and you can fashion a cover for your plant. Frost cloth does not transmit cold so you can go into the high twenties for a short time and the plant stays protected. You can also put poles in the ground that come out in the spring, you put a cover over the plant because the settling of the damp frost is the most harmful to the plumeria.

Thanks for your help tdogdad. I've taken your advice and treated my tree. I will be keeping close watch on it to see if anything else gets mushy or turns black. If it is infected I will continue to cut back and spray.

Also thanks for the tip on the frost cloth. I will be looking for some or buy some on the internet. I am not sure what you mean about the poles though. Do you put them in the ground around the tree and attach the frost cloth to them? How far above the ground do you let them stand out? Someone told me I could purchase that black plumbing insulation they put around pipes to keep the tree safe, but I don't think it would keep the tips from getting frostbitten. The cloth sounds like a better solution.

What I have seen is four pvc plastic pipes about a foot long placed in the ground on four sides of the plant. In winter, metal poles that just fit into the pvc
pipes are stuck in so they are taller than the plant or plants. A plastic ground cloth is spread over the dormant plants so the cloth does not touch the plant. Big spring clamps are used at each pole to hold the cloth. However, if you use frost cloth you can drape it over the plant and secure it to the ground like a loose tent. I remember that Exotic Plumeria in Florida had a frost cloth but it was pricey. I picked up a whole roll at a farm supply for a fraction of the cost. I also thought of making 1-2 foot rectangles with velcro on the long side so you could wrap around stem and arms and tips (for the tips i would make something like a long golf club cover) with a piece for each segment. However, that idea never got beyond the drawing board. Maybe you can find a new solution.

It would seem to me that since 'frost happens' in an 8b location, in the future, it might be better to just dig up the plant and store it bareroot in a garage, crawl space, storage shed or attic.

Dave you are right but in the beginning kms said they had no place to store the plant inside. I was offering an alternative that can work, but most people I know in Texas dig and store.

I found a crop cover in Charlies Greenhouse (Charleysgreenhouse.com) that it says is effective to 26 degrees and is UV stabilized. They say it can be used as a protective wrap for ornamental shrubs. There is a roll of 6' x 50' for about $15 (item #1782) or a crop blanket of 12' x 25' (#1788) for the same price. I do not know this product but you could talk to a customer service rep. on the toll free number about it. Hope this helps.

I also can't dig up the tree due to an inability to handle. She is about 7 1/2 feet tall and weighs somewhere near 300 lbs. I appreciate all the alternative suggestions to digging up and storing inside a greenhouse for those of us who need alternatives but still want to attempt to grow these beautiful plants.