African Milk Tree

[GermanStar]

I purchased and planted an African Milk Tree (Euphorbia trigona) a couple of months ago, and it's doing spectacularly, having grown several inches in height along with some new branches. My concern is the upcoming winter. This plant in tagged for Zone 10b and up, I am in Zone 9, and it is my understanding that they drop dead at first frost. I have been told by a local that placing styrofoam cups on the plants should provide adequate frost protection on those chilly nights, but I'm not so sure. I'm tempted to just dig the plant up and pot it, so I can bring it indoors on freezing nights. I don't want to harm it now, and I don't want to kill it later. Any ideas, opinions?

[Green Mantis]

I think go with your inner feelings, put it in a pot and bring it in????? I could be SO wrong, but hopefully someone with more knowledge will come on? Good Luck.