I was reading in a '05 book that this is true .
Is it true in your zone 5 garden?
I have 2 types of Cleodendrum in my collection. C. ungandense and C. bungei. Both are in containers and overwinter in my attached garage. Both will reach 4' tall by late summer/early fall.
Do you cut it down for winter? Is your garage heated? Do you water it over the winter?