I have several Radicans that look like this (but shorter of course). On a few of them part of the plant looks ok but part has brown dead leaves. SHould I cut back the brown stems and hope for the best?

Terp,
Your gardenia is dead.
Sorry about that. It should have at least
a dozen or so green leaves, it doesn't.
You may not like the answer, but it died.
Look for another little beauty this summer and enjoy it
as much as you did this one.

I always nick the bark to look for green beneath it. If all you see when you scratch off the top layer is brown, then that indicates that part of the plant has died.

I want to ad this response from my local ag extension agent in case anyone else comes across this post looking for answers:

I hate to be the bearer of bad news but my guess is that you will lose this plant. I wouldn't pull it just yet, let is stay until mid April and see what if anything does emerge. I think the biggest problem is that this plant is hardy to zone 8 and we are a zone 7. this year we probably faired as a zone 6. (Mystery gardenia (Gardenia jasminoides âÂÂMysteryâÂÂ) thrives in a well-drained but moist, sandy location in partial to full sun. These gardenias grow well in U.S. Department of Agriculture plant hardiness zones 8 through 11, as they are a subtropical shrub.)The second problem was probably a limited root system. Since it was only planted in the Fall it probably did not have time to get a deep, well established root system established and that could also have played a part in it's demise. I am so sorry.

Karen Neill, Urban Horticulture Agent
North Carolina cooperative Extension Guilford County

Mine looks quite similar to yours - it is about three years old. It is green under the bark - I am going to see what happens as it warms up. See the link below.

I also read this on the National Gardening forum:
Gardenias are hardy to about 30*. If the temps went below that for any extended period of time you may lose it. Don't fertilize it as that will only stress it more. It may drop all its leaves because it's so stressed, but don't lose heart. Give the shrub at least a month to see if there is any new growth. If you aren't sure, just scrape a branch and look and see if there is any green. If you see any green under the bark, there's still life there.

So...I am going to wait it out - I will fertilize mine when it stays warm outside. I'm in zone 7b (Upstate South Carolina). Terpsichore - let's compare notes in a few months - I hope our Gardenias surprise us.

Here is a link that might be useful: What to Do if a Gardenia Bush Freezes

I have 5 cold damaged gardenias. I have hope for 3 of them, as they do have more than 12 green leaves on them. Assuming they make it and start showing signs of new growth, how severe of a cut back should we administer? Should we just cut all of the dead off? Or do a major cut back? Any advise for what to do now would be greatly appreciated!

KS,
Gardenias are evergreen. They aren't suppose to loose their leaves, they photosynthesize all winter long.
They don't go to sleep, like decideous bushes and trees.
As long as there are some green leaves on the bush, it will be able to "eat" the sunlight. It will stay alive.
If there are no leaves left at all, and the period is prolonged, like a month or two or three in some zones, the shrub will die.
Wait until the weather really starts to warm up.
WHen you see life from the gardenia, then see what is dead on it.
Just prune off what is dead. That's all.
Remember, as long as there are some green leaves, you are alright.
Gardenia shrubs are not expensive shrubs, and we had a horribly cold winter this year.
Gardening is like everything, you win some, you loose some.
But whatever you do with your pruning, don't take more than One third of the shrub off in one year.
That is why I told you to just to cut the dead parts off.

Thanks for your help!