The rating from a standard reference (Dirr) is (6)7-9. (6) means for
some varieties zone 6 is the northern-most limit. I have 10 yr old
"Edith Bogue" and "Victoria" that have shown absolutely no winter
damage, ever, here in 6B.

--beeky

Paul wrote:

Hi,
Does anyone know what the USGA Zones for a southern magnolia is?

Thanks in advance.

Paul