It sounds impossible Stan. Please keep us informed of your progress. Plumeria has been very frustrating for me as I have tried different approaches. What kind of cold protection are you using in the ground? In the pot moisture control as well as the winter cold has been my problem,(I think!). Al

Stan, plants do withstand cold better in the ground than in a pot. That said, I think the Celadine must be hardier than most Plumies. This last winter we had only one really cold spell that browned the foliage on banana's etc. So it might not work every year...

My lone surviving plumeria is a "rainbow" type, and I bring it into an unheated greenhouse each winter. Even so I have lost one branch tip each year. On the various plumeria forums I did come across someone in San Jose who grows Plumies in the ground, but he builds a small plastic covered greenhouse over each one for the winter.

On a related note, I have heard good things about the heated pots which are available - sort of like a heating pad built into an insulated pot.

Chad

Al,the one thats lived outdoors in ground is with my cacti and succulents in the front yard. Thats one of my warmest spots on my small property-it gets reflected heat from the sidewalk,and street-newly paved and jet black. I planted it also mound style. That is, I dug a hole half the depth of the gallon pot it was in and mounded soil around it. Its made it through the winter fine-even has extra stem buds on it.It was never covered in any way. And we had that Dec cold streak push temps to a hair above freezing two night in a row. I wouldnt even think of watering them in winter,and dont worry the mound style is too dry in summer. Just water a couple times a week in summer seems enough.
Chad-I think Celadine might be THE hardiest of Plumerias. Another I hear almost as hardy is a peach I havent been able to find. So,I go with what I got!
btw,Chad I had 'Aztec' it mushed by December,two years ago,just from rain.

Ah,what the heck,since the spammer dredged this one up...Celadine is in its second summer in ground..I had some problems with tip rot by the end of winter...its responded by making three tips where there might have been one to a branch. SLOW to leaf out..just now in mid July has it grown larger sized leafs.
I would say a real specialty plant for the bay area..every year is iffy. I can only hope one summer it will flush a heavy growth of leaves to tell me -"It's made it".

Stan, I took your advice and ran with it... I got seeds from Celadyne and have about a dozen seedlings around a foot high now. Hopefully I'll get some flower diversity as well as hardiness from this bunch.

I overwintered my 'rainbow' in the unheated greenhouse right next to my "warm enclosure" and I had no damage at all this year. The warm enclosure is a mini greenhouse with a soil heating cable on a thermostat for heat; it keeps the coleus etc. alive for me.

Chad

When you get to planting your young Celadines outdoors Chad-the key is sun,sun,sun and more sun. I wouldnt grow any groundcover at the base of the plants either-you want the sun to warm the soil as much as possible. I do have some Aeoniums on one side of mine-but they grow with plenty of gaps..andd the sunlight makes it to the base of the Plummie even on that side.
Another key-STAKE them. They have wobbly roots by the end of winter. A good staking helps to stop any wiggling and root damage.
And when they say its going to be 32-33,in that range..its worth it to cover them. I get maybe 3-4 nights of near freezing per winter and covering is worthwhile to preserve the other 361 days of growth you got.
The hardest part is you might want to remove any flower buds the first two years...you want all growth. Here in the bay area ,they seem to alternate between flowering years with few leaves and growing mostly leaves years. Thats an option you might or might not want to follow,or try on some plants since you will seem to have a few to play with. Good luck!
btw,When mine gets a few more leafs,an updated pic..