Many of the fern fiddleheads in the bogs are now harvestable delicacies. Some are just emerging and will be ready in a few days. Fiddleheads are the tops of ferns just before they unspool into lacy plants. All fiddleheads have toxins, but some have a tolerable amount if cooked well.
Around here, the Ostrich Fern fiddleheads are preferred for the table; Bracken and some other fiddleheads are too toxic to eat. Safe fiddleheads are eaten hot, with hollandaise, butter, garlic, vinegar, lemon or other sauce; they’re also eaten cold (after being cooked) in salads with any dressing. (Brooklin, Maine)