Your post has been sitting there for a few days without a response. I was hoping someone with experience in your climate would chime in with advice.

My suggestions would be to invest in some frost cloth. When the temps are due to drop overnight where frost is possible, you can drape the cloth over the plant. Frost cloth can touch the tips without damage, whereas normal cloth or tarps will transmit frost temps to the tips and damage them. Some actually string Christmas tree lights along the branches and turn them on on cold nights to keep the branches warm.

Plumeria hate cold wet roots. Since you get so much rain, be sure the soil they are planted in drains well. Another option is to raise the beds the plumeria are planted so water drains away. Since your plants are obviously tolerating the conditions fairly well, I wouldn't make wholesale changes, just watch the weather and try to avoid freezes. Some people actually dig up their plants for the winter and bare root them in the garage or closet. Then they replant them in the spring. The plants seem to tolerate this well. Others plunge their plumeria, sinking the potted plant in the soil in the spring and pulling it out in the late fall/winter. They store the plant, pot and all, in the garage or house.

Hope this helps.
Mike

Howdy Donn wHo . . . :-)

I don't have much plumie experience but I do live in SF with a few plumeria in the garden. From the little I've learned I think you should be better off than I since you're in San Leandro and get a longer hot season there. I have a peculiar spot on the east side of Telegraph Hill that almost never gets fog and so it's possible to grow plumeria here, there's enough heat and sun in the right sheltered location.

What I did discover this season though, is the danger of a bad rainy year. One of my two big trees (6'+) was done in by excessive rain. My other big tree (an Aztec Gold) survived almost unscathed (had to prune just one tip). From this lesson I would echo Mike's comments above about planting in raised beds to maximize drainage and once this growing season is over I plan to replant my Aztec Gold 8-10" above it's current location with lots of sand and perlite underneath it.

The Aztec Gold has a rep for being one of the tougher plumies, I don't know if there are others in this same category but it's definitely worth searching for these tougher varieties if you want to grow plumies in the Bay Area.

Since you're starting with cuttings you may want to just keep them in pots for the first few years. Like that you can bring them in over the winter and then just plunge the pots back in the ground in the spring. Personally, in San Leandro I wouldn't worry about winter temperatures but I would be concerned with an abnormally long, wet winter.