Caerulea came back in my 6b garden after this past winter. (now if it would just bloom for me....I think I fertilized it too much)

You might want to look into P. Incarnata as well. It easily would survive your zone and it is easily just as nice as Caerulea.

~Chills

Caerulea is hardier then zone 8. I'm not far from you, in Montgomery County (7a) and it will survive the winter here. P. incarnata and incense will also survive our winter.
Karyn

Many caeruleas will not bloom unless some old wood survives from the previous year, and the ones that do bloom on the new growth from the roots, often do not bloom until late in the season. I would suggest that you cut it back to just a couple of trunks a couple of feet tall before temps drop below 20F, and cover them for the winter with some sort of insulation.

I am also in Baltimore and my caerulea I bought from a local nusery survived last winter.
It is planted next to a south facing wall of my house. I cut it back to two branches in early spring.
It started blooming about three weeks ago. Now, if only I can figure out how to get it to set fruit.
Andrea:)

My caeruleas will set fruit but they've always been empty. Just little sacks of air, no pith, no undeveloped seeds, nothing.
Karyn

That is great to hear. I really love this plant. Thanks for the information!