Brenda, Google up Rhubarb Redleaf disease and see what you think? From looking at the red leaves, I'd say it fits the description.

Sharon

Here is a link that might be useful: Redleaf

Hi, My rhubarb is looking terrible. It's been in the ground for maybe three years. This year the leaves are turning brown, yellow and with some red. Some of them have turned real brown and dried up. If I could figure out how to post a picture, would do that so you can give better advice. Unfortunately there are black walnut trees all around us but they aren't too close. I understand that juglone given off by black walnuts is bad for rhubarb. We live in central NYS. Any advice would be helpful. Thanks, Nancy