Ostrich Fern

Set ostrich fern crowns in partial to full shade where the soil stays constantly moist, planting in spring as growth begins. Heavy, moist soil suits it best, though it adapts to lighter rich soil; give each clump room for a 2 to 4 foot spread. In the wild this fern grows along cool woodland streambanks and river floodplains under maple and ash canopy, so it only thrives where a planting replicates that shade and constant moisture.

In spring, lift a crown from the edge of the colony and split it so each division carries a crown and a healthy share of roots, then replant at the original depth in moist shade. The stout rhizomes send out slender underground runners that form new crowns, so a colony divides cleanly in spring while growth is starting and the divisions can root before summer heat.

Give ostrich fern a shaded, moist area with a defined border and expect it to fill that area; it is best sited where you do not mind it spreading. In spring, when crowns are breaking, lift any offshoot crowns the underground runners have pushed past your border, taking a share of roots with each. Replant the divisions in moist shade elsewhere or compost them. Do not rely on it behaving in a small mixed planting. Penn State Extension states the fern is strongly competitive and can push out less vigorous shade species, so it is not ideal for small gardens with mixed plantings, and that deeply shaded moist areas with borders let it thrive and remain confined. NC State adds that the stout rhizomes send out slender underground runners forming new colonies, which can be weedy, and that crowns are divided in spring - so spring is when offshoots are lifted cleanly and can root before summer heat.

Water whenever the soil surface dries, especially on plants getting any direct sun. Ostrich fern tolerates sun only where temperatures stay cool and moisture is ample; in warmer zones keep it shaded and wet. The fern is adapted to streambank soil that never dries out, and fronds tatter and brown early when the crown runs short of water in summer heat.

Pick fiddleheads while still tightly curled, at 2 to 6 inches tall, and only from healthy crowns carrying at least four of them. Take no more than half the emerged fiddleheads from any one crown and do not come back for the later ones that season. Harvest only ostrich fern, identified by the deep U-shaped groove inside a smooth stem and the thin brown papery scales. University of Maine research followed harvested crowns for four years and found that stripping all the emerged fiddleheads each year left crowns producing very few or none, because the fronds are the crown's only means of rebuilding its reserves.

Rinse the brown papery scales off under running water, then boil the fiddleheads in lightly salted water for 15 minutes or steam them 10 to 12 minutes before they go into any other dish. Cook in small batches rather than packing the pot, and refrigerate them until you cook or preserve them, within a week. A 1994 CDC-investigated outbreak traced foodborne illness to raw and undercooked fiddleheads, and University of Maine testing showed a crowded pot does not heat the coils through.