In article ,
says...


Here is a hardy rosemary good to zone 6.

http://www.ehow.com/list_7367161_har...ry-plants.html

I've lost quite a few here in zone 5 but wall of water can keep it
alive if the moles/voles miss them. One is perking along right now.
One of 4 planted 2 years ago.

OP may want to look into.

South side solar gain maybe trapped. Look into "passive solar designs".

My experience differs in Zone 5 London Ontario.

Rosemary doesn't survive our winter outdoors. Full stop.

The only way we can overwinter rosemary, is indoors.

We have two, ten year old potted ARP rosemary plants. They withstand
frost very well and have survived the occasional subzero (to -4 celsius
uncovered and -6 covered) late fall night but when it looks like winter
is settling in for real,they get a final shearing and are put on the
table by my office window.

ARP was originally considered to be hardy to zone 5, and then it was
supposed to be hardy to zone 6. My favourite herb seed supplier
considers it hardy to zone 7. YMMV