Keeping lavender and rosemary alive during winter
I live in zone 5b and for the last 3 years I had a lavender and a rosemary plant growing on the south side of my house which did fairly well though the lavender never blossomed. I had to move out of the house to another town 20 miles away and so potted them into large pots. Needless to say, they did not survive the winter as there is alot of shade here at the new house.
This year I bought some rosemary plants, and a couple of lavender, one was a hybrid which is supposed to be more hardy, but already seems to have died. I have them in large pots and experimented with the soil, using alot of sand in one, some with rocks, some with potting soil and all with perlite and brought the Ph level to about 7. My concern is that I don't want them to die, especially since one I started from seed was successful. I am wondering if I need to overwinter them all indoors, and if so, if using grow lamps in the light fixture will help and also if running the ceiling fan will help for ventilation. I have a few outdoors still but need to figure out if I should bring them in as in order to get adequate sun they are out in the middle of the yard with nothing to block the cold north winds.
It has been fairly warm so far, but I want to make sure they stay alive. I maintain the room at 70 degrees and it has an east and south facing window that I keep the blinds up and the lights on with a flood grow light and a 60 watt incandescent on for 12-14 hours a day.
I have also moved my lemon balm into the room and they are doing great and have propagated a rosemary cutting successfully so far in there.
Are there any tips anyone could give me on this?