No matter the season, cinnamon fern is a dramatic accent for shaded areas. It displays lush, bright green fronds and tall, cinnamon-colored fruiting spikes in spring and summer. When the weather cools, the leaves take on beautiful orange, peach, or copper hues, and throughout winter, the darkened fruiting spike persists to provide contrast and structure to the landscape. The fertile, spike-like fronds, which are separate on this species, emerge in spring with a covering of silver-brown wool. They grow stiff and erect, covered with specialized pinnae (leaflets) that turn the upper portion into a thick spike of fruiting “dots” that change in color from green to cinnamon or chocolate brown. The “dots” are sori, or small structures that contain spores for reproduction. Fuzzy fiddleheads of sterile leaves soon follow, usually maturing into 2-4’ fronds that spread outwards in a vase-like shape. 
 
In ideal conditions, cinnamon fern may be 6’ tall. It grows naturally along streams and does especially well in damp, shady areas with rich soils, though it adapts to other well-drained soils. While it thrives in shade, it can tolerate sun as long as the soil is consistently moist. The rhizomes spread vigorously from shallow crowns to form a stunning groundcover of tall, textured fronds. Older rhizomes, which are tough and woody, are sometimes harvested for use as a potting medium known as osmunda fiber that is used for orchids and other epiphytic plants. Cinnamon fern’s height and shape resemble those of two other Ohio natives--ostrich fern and interrupted fern. Cinnamon fern can be easily distinguished from the others by its brown fruiting spikes and by the tufts of orange hair (“hair in the armpits”) at the junction of the main stem and leaflets. It also has furry, cinnamon-colored fibers at the base of the fronds (the common name refers to the color of the fibers and the fertile spike). 
 
Plant ferns 2’ apart in spring or early summer with the crowns just above ground level. It's safe to plant this fern near black walnut trees. Dead foliage, which makes a nice mulch over the winter, can be removed in spring. Spring is a fine time to divide plants with two or more crowns. Make sure each piece has a root system, and keep the divided plants watered after transplanting. Deer and rabbits tend to avoid browsing on the rough-textured leaves of ferns. 
 
Native habitats include marshes, wet woods, bogs, and swamps. Use in shady borders, woodlands, rain and shade gardens, containers, as a groundcover, and along streams and ponds. 
 
Plant Characteristics: 
Grows 2-6’ tall and 2-5’ wide. 
 
Best sited in part or full shade. 
 
Prefers moist, humusy soils but adapts to lesser conditions. 
 
Compound leaves are lance shaped and up to 40” long and 10” wide, gradually tapering at the tips. Deeply lobed leaflets are rounded to slightly pointed at the tips. The fronds grow in a circular clump with the fertile spike in the middle. The stems are green and slightly grooved, and the root crown is bristly and black. 
 
Wildlife Value: 
Cinnamon fern hosts 8 species of Lepidoptera in central Ohio, including American angle shade, silphium borer, black arches (all pictured here in order of mention, black arches with its larval form) and marsh fern moths. Ruffed grouses eat the fiddleheads, and the wool on the emerging fronds is used for nesting material by yellow warblers and hummingbirds. Brown thrashers and veeries use the plant for ground nesting. 
 
Medicinal, Edible, and Other Uses: 
Native Americans used the plant externally to treat rheumatism, headaches, joint pain, and colds. 
 
Caution: All parts of the plant are mildly toxic and can cause nausea, dizziness, and headaches.