I have a sego that was planted about 20 months ago. Last winter we had a deep frost, but we covered the sego and it seemed fine. In the spring it sprouted a whole new layer of fronds. About 3 weeks ago, it started yellowing. We went on vacation and when we returned 2 weeks later, it had completely wilted and the new growth that had begun in the center can be pulled out easily. I really hate to lose this plant. Is there ANYTHING I can do to try and save it?