In all likelihood, it's fine. It sounds like the cold weather may have gotten to it at the end of winter. If you just keep it watered properly, it should grow back new leaves. I've had bamboo that completely defoliated make a complete recovery, so avoid hasty action. If it does not grow back the leaves in the next two months or so, or any of the culms turn a flat, tan color, that means that some of the aboveground growth has died...but the root system is probably just fine. You could choose to prune then when you're sure which of the culms are really dead. Also be aware that any pruning back of the culms will be permanent. The culms grow to their full size in the year they come up. Pruning will permanently subtract whatever you chop off. Unlike trees or bushes, pruning will not stimulate new growth or more branches.

(P.S.: It's called Yellow Groove, not "Grove.")

Hi I have a Yellow Grove Bamboo plant also. I live just outside of Buffalo, Ny. where our winters can be brutal too. My bamboo stays outside all winter and when spring comes, almost all my leaves are yellow, with a few green leaves at the bottom. I was told not to cut or pull off the leaves or branches, because it does come back. Last spring, I looked closely and saw new leaves opening under the yellow leaves and as it got warmer here, my bamboo turned green. The yellow leaves that fall on the ground around the plant are sposse to help the plant too. I feed my bamboo fertilizer too to help it grow strong and it helps it going into the winter seasons. Goodluck, Janet