Photo credit: Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA SCS. 1991. Southern wetland flora: Field office guide to plant species. South National Technical Center, Fort Worth.
FIRST IMPRESSIONS: Osmunda cinnamomea is an elegant and entertaining fern. In spring, fuzzy reddish brown fiddleheads emerge and dramatically unfurl. The result of this effort is a rosette of large bright green arching fronds. As these sterile fronds reach mature size, wands of cinnamon colored fertile fronds materialize. Plants turn a brief yellow in autumn and disappear for most of the winter. This fern expands by rhizomes to form colonies that thrive in moist or wet shady sites
HABITAT & HARDINESS: Osmunda cinnamomea occurs in eastern North America from the southeastern Canadian provinces to Maine and south to Florida and west to Minnesota, Oklahoma and Texas.
This fern is usually found in shady, wet and relatively undisturbed sites like shaded seeps, low sandy woods, sandy or peaty swamps, bog margins, sandstone ravines and sandy stream banks.
Hardiness rating is from USDA Zones 2-10.
PLANT DESCRIPTION: Osmunda cinnamomea is a bold rhizomatous fern with a striking vase shaped habit. Plants have a substantial woody crown that produces dark wiry fibrous roots and short spreading rhizomes.
This is a dimorphic fern with separate sterile and fertile fronds. The unfurled sterile leaves emerge from the ground in late winter as pubescent coiled fiddleheads.
The fiddleheads expand into 3-5’ long sterile fronds with 12-25 pairs of leaflets. The bright green pinnae are narrow with 10-20 pairs of oblong rounded lobes. The lower part of the rachis and the underside of the pinnae have persistent tufts of reddish brown hairs.
The fertile fronds are covered with cinnamon colored spore clusters and reddish-brown wooly hairs. These upright spore bearing stalks emerge in spring, release their spores and collapse by summer’s end.
The sterile fronds turn yellow before dying to the ground for the winter.
This fern is typically about 3’ tall with an equal spread. In an ideal cool moist site plants can reach 6’.
CULTURAL & MAINTENANCE NEEDS: Osmunda cinnamomea grows best in dappled to light shade with rich consistently moist or wet soil.
Plants thrive in humus rich sandy or peaty soils with acid pH.
This fern tolerates part sun in wet sites or garden situations with regular irrigation.
Plants are pest resistant and unpalatable to deer and other herbivores.
LANDSCAPE USES: The dramatic feathery foliage of this fern make it a lovely and useful Accent for a Shade Garden or Water Garden. In appropriate sites, Osmunda cinnamomea matures into a verdant and soothing Groundcover or Mass. This fern can control erosion and serve as a valuable component of Deer Resistant Plantings, Low Maintenance Plantings, Rain Gardens, Wetlands and Wildlife Gardens.
COMPANION & UNDERSTUDY PLANTS: Try pairing with Aquilegia canadensis, Aruncus dioicus, Carex grayi or Chelone glabra.
Matteuccia struthiopteris has similar cultural needs and can be substituted if needed.
TRIVIA: This fern produces large edible fiddleheads that are a gourmet treat when sautéed in butter.
Osmunda cinnamomea is easy to differentiate from look-alikes due to the distinctive cinnamon colored fertile fronds and the conspicuous orange hairs beneath the pinnae and on the rachis.
Similar in appearance to Matteuccia struthiopteris but the pinnae undersides have simple unbranched lateral veins. Osmunda cinnamomea, on the other hand, has forked lateral veins beneath the pinnae.
For more information on this plant, visit the USDA PLANTS Database: http://plants.usda.gov/java/profile?symbol=OSCI