Plant files says this is hardy to 20° but mine did not take 34° last week. It's in a container and when I noticed the damage I brought the container in the house and placed it under some grow lights. It's not looking any better - a bit worse actually.
Is there a way to save this plant? It was looking sooooo good before it got all limpy. I'm thinking to cut back the stems and let it start again but I don't know if the rule of thumb for pruning trees also holds for plants. Something like: don't remove more than 30% of the limbs at one time
Any suggestions on how I can help this baby survive?
Being in a container will typically knock about a zone (10 degrees) off the hardiness, so that could be part of your problem. But also remember there's a difference between the leaves suffering frost damage and the plant being killed--most likely the roots are fine and the plant will come back. I have several plants that look severely frost damaged every year--they lose all their leaves, etc but then they come back in the spring. Hardiness listings account for the lowest temperature the plant will survive, not the lowest temperature at which it will keep all its leaves and look pretty and green.
For any frost damaged plant, the best thing to do is leave it alone until spring. The frost damaged portions can help protect undamaged parts of the plant if it is exposed to more cold weather. Plus it's hard to tell which parts are actually dead and which still have some life to them until it starts putting out new growth, so even though it's indoors now and you don't have to worry about future cold spells, I'd leave it alone until you start to see new growth. Feel free to remove dead leaves, but I wouldn't trim it just yet. Once it starts to put out some new growth, you'll be able to tell if any of the top part is still alive or if all the new growth is all coming from the roots, and at that point you can trim out any dead parts. Also--don't worry that it's looking worse now that you brought it in, that is fairly typical for cold damage, it normally takes several days or even a week or two for all the damage to show up.