Starting from seed indoors hardiness zone question

Hello folks! new member here and newbie to SFG..Anyhow, I have some experience growing indoors under lights(mainly lettuce) and after purchasing/reading Mel's book we are starting some beds for this coming spring, yahoo! can't wait..
We are also in the process of converting a DIY gazebo into a soon to be unheated(for now) greenhouse from recycled windows and poly sheets for roof..
Question is(finally) in zone 8b high desert Ca. if I use an already built coldframe for seedling hardening and put the coldframe in my un-finished greenhouse which is ~60% finished, can I use a higher hardiness zone e.g 9-9b if I'm using the coldframe..Starting seeds indoors the usual suspects broccoli, cabbage,green onions, etc. IOW cold hardy plants/greens for now..
As stated above I have experience growing indoors, and have grown toms and peppers outdoors in containers from purchased transplants with good success..TIA.
Tony

Tony

In my complete inexperience of this subject, to me it makes perfect sense that if you put a container within a container you will be able to up the hardiness zone. I am comparing it to double glazing the windows of your home.

Hi Susnton, welcome to the SFG Forum.
Try these links for some info:

http://www.almanac.com/gardening/planting-dates/zipcode/92345

http://www.johnnyseeds.com/

Thanks kelejan, exactly my thoughts, just wanted to hear some more opinions, from others as well..
Thanks camprn!.. I've seen that site as well as others, and wanted to know if it was ok to perhaps start my indoor seed sowing a lil earlier and use an upped zone as a guide other than what the average last frost dates in my zone(8b) AFAIK..
Seeds are rather inexpensive, so I'm gonna start a few earlier and others at the recommended time frame..Thanks again and look forward to any help/tips you or anyone else cares to share.
It's a little wet today when working on my greenhouse, but will post some pics of it and some indoor lettuce seedlings going under lights and some jalapeno peppers too..I know I know a little early but it was an experiment/trial if you will!..
Oh btw, thanks for the warm welcome..

That's the beauty of experimenting with seeds, It does not cost the earth. Lettuce know how things turn out.