Plant Delights Nursery lists aloysia virgata as being hardy to zones 7b-10, and in their climate, it dies to the ground each winter, but returns. -5-6 degrees celsius=32 degrees farenheit? I'm in zone 9 here and though it does occasionally get that cold in this area, our property hardly, if ever, gets any frost, so I'm not much help in determing hardiness from personal experience. I'm sure someone else will come along from a colder zone to give their experience with this plant.....
