Ostrich Fern Fiddleheads

The plant

Ostrich fern (Matteuccia struthiopteris) grows in big colonies on rich, moist ground, especially river floodplains and stream banks, throughout Wisconsin. In late April and May its new fronds come up as tight green coils, the fiddleheads, from the crown of each clump. By summer the fronds stand three to six feet tall in a vase shape, like an ostrich’s plume.

Only the ostrich fern is eaten as a fiddlehead in this region. Every fern makes coils in spring, but others are inedible, and some are carcinogenic.

Identification

Maine Extension’s three features ¹:

1. A brown, papery, scale-like covering on the coil, which rubs off.
2. About 1 inch across when tightly coiled.
3. A deep U-shaped groove on the inside of the stem, like a celery stalk.

And:

• The stem is smooth, not fuzzy or hairy.
• They grow in clumps of several fiddleheads from a crown.
• Last year’s dead fronds stand nearby: the green fronds lie flat and brown, and the separate fertile fronds, dark brown and stiff, stay upright through winter. They’re a good way to find a patch before fiddleheads come up.

Look-alikes

• Bracken fern (Pteridium), common on dry, sandy, sunny ground in the north, comes up as a single fuzzy stalk with a three-part claw at the top. Bracken is carcinogenic and should not be eaten ¹.
• Cinnamon and interrupted ferns have woolly, fuzzy coils.
• Lady fern fiddleheads are small and scaly but lack the deep U-groove.

Harvesting

• Pick fiddleheads when tightly coiled and only an inch or two of stem has emerged.
• Take no more than half the fiddleheads from a clump, often given as three of the five to nine in a crown, and leave the rest to grow. A crown stripped bare weakens or dies.
• Snap them off by hand near the ground.
• Fiddleheads are greens, not fruits or nuts, so on DNR land they need permission.

Cleaning

Rinse under cold water and rub off the brown papery scales, then soak in clean water and repeat until the scales are gone. Trim browned ends ¹.

Cooking safely

Raw and undercooked fiddleheads have made people sick. An outbreak in 1994 followed raw or undercooked fiddleheads, with diarrhea, nausea, vomiting, cramps, and headache starting 30 minutes to 12 hours after eating and usually lasting less than a day. The cause isn’t known for sure, but thorough cooking prevents it ¹.

So ¹:

• Boil 15 minutes in plenty of lightly salted water, in small batches, or
• Steam 10 to 12 minutes.
• Discard the cooking water.
• Only then sauté, bake, or add to other dishes. Sautéing, stir-frying, or microwaving raw fiddleheads isn’t enough.

Cooked fiddleheads taste like asparagus and green beans with a grassy edge. They’re very good with butter, lemon, and ramps.

Preserving

• Freezing: after cleaning, blanch 2 minutes, cool in ice water 2 minutes, drain, and freeze. Cook them fully before eating.
• Pickling: use a tested recipe with vinegar brine, processed in a water bath canner ¹.

What to take from this

Eat only ostrich fern fiddleheads: tight coils about an inch across, smooth under brown papery scales, with a deep U-groove inside the stem, in clumps on floodplains. Avoid fuzzy coils and bracken. Take no more than half from a clump. Clean off the scales, then boil 15 minutes or steam 10 to 12 before eating or sautéing.