I was dismayed for several weeks and then I thought: why couldn't I add some more fabric on to it? I had nothing suitable in my fabric stash and I am only buying dress-lengths of fabric right now, so I turned to my scrap bins.
I pieced together a long enough swath and backed it with muslin, so the raw edge of the original terracotta fabric is encased between the muslin and the patchwork.
Then I made up the difference in the frayed area with more patchwork so I wouldn't have to trim down the whole edge and lose width.
Whew. I'm quite pleased with the rich, whimsical look. It cost $15 plus scraps and thread.