are the plants showing any green anywhere? or is it all brown and dark?

I did notice one small branch w/ a 1/2 inch of pale green at the base of the bamboo. The rest is all brown and black. So sad to look at.

Ya, that sure doesn't sound too promising, but I think planting them outside like you did will give the best chance for a recovery if that's at all possible. I'd keep them wetered but not soggy. They likely wouldn't use much water without any leaves. Good luck. My guess is it's time to look for replacements.

If there is really a small amount of green at the base like you say, this might mean that even if all the culms and leaves (above ground) died, the rhizomes could still be alive. You may not see any growth for a while, and certainly none from the dead above ground portion, but I'd give the underground "stuff" some time to show its toughness. Moderate water is about all you can do for it.

Thanks for the advice. I'll continue to water it and keep an eye out for any new growth. Keeping my fingers crossed too.

Don't need to fertilise until you see new growths. If it did survive and throw up new growths, make sure you mulch it well for this coming winter.

Hi... just my 2 cents... I had a simular problem with a plant. It looked real bad... bone dry with just a hint of life left...I mixed up some liquid fertilizer 12-12-12 and soaked it...allowed it to nearly dry again (about a week) and soaked it again. New green slowly appeared and began to grow again.
Might be just the boost the boo needs to get kick started.
Best of luck
CJ