Hi Lori, yes you can freeze them. Just keep in mind they will be quite soft, and loose some water during the thawing process.

Hi Allie, while you could certainly thaw and pickle them, keep in mind that freezing/thawing the fiddle heads will change their texture and they will naturally be softer and no longer crisp. If you are doing a hot pickle, I would suggest not thawing the fiddleheads first and instead adding the hot pickling liquid directly to the frozen fiddleheads to preserve as much texture as possible.