when was the last freeze??

ken

That's frustrating. I know that barberries like lots of organic material in the soil. I would try ammending the soil with Miracle Grow Garden Soil for Trees and Shrubs and then mulch around them really well with 2-3 inches of organic mulch and then see what happens. Hopefully they will pull through.

Here is a link that might be useful: Solving Problems of Japanese Barberry

did they by any chance get dry?

I have two small barberries in a trough that get their roots pruned sometimes twice a year and they never miss a beat so I doubt that's it.

tj