And are they surviving? How are you protecting them?
I was thinking of putting these in the ground this Spring and see what happens next year. Also, plant to cover them for the winter in place either with tarps or bubble wrap, or something besides mulch. Same goes for the four Brugs I have.
Any responses are appreciated.
A.
Anyone in Zone 7/8 growing in ground w/mulch for winter?
Antoinette, we had many that were killed here in Southern California in Zone 10 during a record-breaking freeze. Many collectors lost big trees, and nearly everyone suffered branch damage and dieback, including me. Here's a link to one collector's damage: http://www.mauiplumeriagardens.com/forums/index.php?showtopic=10074&hl=damage
There are some big trees in places like Arizona in Zone 9b, but they have big concrete structures around them which help to raise the ambient temperature and which create microclimates. They are also big enough to withstand some dieback and not die completely. These trees are few and far between.
Plumerias are really only hardy to Zone 10. I wouldn't risk yours in any zone less than Zone 10 unless you built a protective structure around it and added heat and lighting, but then you would have to make sure that the ground didn't freeze around the root system. If you built a greenhouse around a planted one, you might get it to survive in the ground if you took the appropriate measures to protect the roots as well.
i'm pretty sure if it is in the ground in a "real" zone 8 (no stretching.... i mguilty of that :-) ), you're pretty safe from freezing the roots, but unless there is a substantial structure built around it, you will lose the plumie regardless of wether the ground freezez or not.