Sword ferns offer majestic garden beauty

The largest species in its genus, Sword Fern, (Polystichum munitum) is a majestic semi-evergreen native with sword-like fronds (leaves) rising gracefully three to five feet from a central, scaly crown rhizome. Classically named, “poly” is Greek for “many” and “stichos” is “line” or “row” referring to the parallel rows of sori (spore sacs) found on the underside of the fronds. The species name “munitum” meaning “armed with teeth,” describes the edges of the alternate leaflets lining the central rib of the frond.

Sword Fern is found abundantly in the coastal temperate forests and in areas of the inland temperate rainforest in central BC, Canada, extreme northeast Washington, north Idaho and northwest Montana. It prefers full shade to partial sun and moist, humus-rich soil, but it is highly adaptable in garden settings.

Many of the leathery, dark green fronds live from 1.5 to 2.5 years. Dead fronds remain attached to the crown rhizome and can be removed to improve garden appearance. Old fronds can also be removed in the spring as the new fronds emerge in tight coils covered in light brown hairs, unrolling as they extend. These new fronds are commonly called “fiddleheads.” Letting dead and dying fronds overwinter in place helps protect the crown rhizome from extreme temperatures.

Ferns are non-flowering plants, reproducing by rhizomes and spores. Spores are produced in rows of round, light rust-colored sori on the underside of the frond, maturing in late summer. A mature Sword Fern can have from 75 to 100 fronds, each producing hundreds of sori in a season.

Sword Ferns are generally pest- and disease-free and are not usually bothered by deer and rabbits. The elegant, arching fronds are long-lasting as greenery in floral arrangements and are widely used in that industry. In fact, the Royal Horticultural Society bestowed its prestigious Award of Garden Merit on Sword Fern for its commanding appearance and many outstanding features.

The lush foliage provides cover and nest sites for birds, small mammals and even deer. Black bears have been known to use Sword Fern fronds to pad their dens for winter hibernation. Native peoples had numerous uses for ferns. Maybe borrowing an idea from local bears, fern fronds were used as mattresses as well as mats for drying fish and berries. In cooking, fronds lined pit ovens filled with camas (Camassia quamash) or wapatoo (Sagittaria latifolia). Fern rhizomes were boiled, baked and steamed as a food source, and numerous parts of the plant were used to treat ailments from dandruff to tonsillitis.

Sword Ferns add a lush texture and rich color to even the darkest corner of a garden year-round. They work well in shady beds and borders and as a ground cover in a woodland garden. Easy to grow, and once established, Sword Ferns require little maintenance. The rhizome can be divided in the spring to start new plants.

Sword Ferns grow in the Moist Forest Habitat of the North Idaho Native Plant Arboretum, 611 S. Ella Ave. in Sandpoint. Pictures and a description are on Page 212 in “Landscaping with Native Plants in the Idaho Panhandle,” a KNPS publication available at local bookstores and the Bonner County History Museum.

Native Plant Notes are created by the Kinnikinnick Native Plant Society. To learn more about KNPS and the North Idaho Native Plant Arboretum, visit www.nativeplantsociety.org.