I planted one of these a couple of years ago here in zone 5b, and it did not survive the winter. Have others had problems with its hardiness?
Do you mean autumn fern Dryopteris erythrosora? That one is always very late to show up. I thought I'd lost most of mine but I think they've all reappeared, although I need to check on one... They were definitely weakened by this winter though.
If you are referring Dryopteris (autumn fern), they are quite hardy. They can be a bit late to emerge, sometimes late May, perhaps early June at the latest, but if they're not up by now, they're goners. I've had numerous clumps for many years, all survived this past whopper of a winter easily and are growing gangbusters, so I'm surprised you lost yours. Was it planted in preferred conditions?
A couple of very small fronds emerged, then died off. This was two years ago. It is rare that a plant doesn't do well in my gardens, it was well sited and planted. Thanks for your responses, maybe I will try it again sometime.