My house faces north and I had the same situation, plants that froze to the ground in front, but fared just fine in back, and even two similar plants in different parts of the front or back yards faring completely differently through winter. You can't underestimate the power of micro-climate zones in any area.

Your idea about finding a neighbor's surviving plant and getting a cutting sounds like a good one. I've also heard Samoan Fluff and Celadine are very hardy, and easier to find than varieties like Sierra Madre. Someone else may know more but I'd read somewhere that Key West Red is very tough and fairly cold-hardy, though I would probably place it next to a structure to be safe. That one would be nice if you want a richer color and lower growth habit.

I ran across an interesting list--don't know how reliable it is--but you may want to check it out in the link.

Jen

Here is a link that might be useful: Arizona cold-tolerant plumeria list

Just a note: I have lost several Aztec Golds. Wildfires, and a large jeannie moragne to mild frosts so I question their names on the cold tolerant list. I find most reds are the least cold tolerant. Bill

I think it all depends on your micro climate and how well you protect them. Here in Phoenix, we had an especially rough winter, where temps got down to 28 degrees at my house, however I only lost one plant, which I believe was not due to the temps, but actually the heavy subsequent rains we received while it was still dormant. I used frost cloth, burlap, and topped it off with xmas lights and they all came out ok with only a few black tips, which already have 5"+ new branches on them!

Thanks all. Celadine seems to come up on every list as being hardy. Perhaps that is the safest choice for me at this point. Obviously a lot is known about that cultivar since it is so popular, so it feels like a solid choice to me. I might hold off until next spring though... gives me more time to gather statistics, evidence, etc.!

If I were planting a recently rooted plumeria, I would ovewrwinter it in a pot in the first year and then plant it in the ground the following year, if you are in fact on the esdge of a climate zone prone to freezing. The first year is the most critical in overwintering a plumeria plant.