You are exactly right, Hetty, about digging up the Plumeria for the winter. I live in zone 8a (was 7b for decades) but we get really hard freezes here in NE Mississippi. I dig up all my Plumeria in early October, whether they are in the ground or in pots, shake off most of the soil, and just lay them under my oak trees, allow the leaves to turn yellow and fall off. Before the first frost, which could be 2-4 weeks after digging them up, I remove what leaves are left, wash the rest of the soil off, take cuttings from the larger plants, and put the plants in large, heavy contractors bags, according to variety. Be sure you allow the rooted plants to dry thoroughly before bagging. The bags will thus have a mixture of cuttings and rooted plants. The bags either go in closets or on my enclosed porch for the winter. They will spend the next four or so months completely dormant in the bags. When spring arrives, and there is no further chance of frosts, I take them out, perhaps take a few more cuttings and put the rooted, though dormant plants in the ground or in pots. I pot up the cuttings and root them.
but according to the USDA I am 10A.. 
