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Woodwardia fimbriata

Family: Blechnaceae
Pronounced: ad-ee-AN-tum a-LEW-tih-kum


Geographic Origin:
Washington, Oregon, Califonia, Nevada, Arizona and British Columbia.
Plant Group:
Sunset zones: 4-9, 14-24.
USDA zones: 8-9.
Heat zones: 9-8.
Mature size:
Height: 6 feet (2 m).
Width: 3-9 feet (1-3 m).
Leaf attributes:
The evergreen fronds can reach 6 feet tall, although some of the largest ferns have reached heights of 9 feet in wet coastal areas. Green fronds are lance-shape, pinnate-pinnatifid.
Growth habit:
Clump forming.
Partial shade.
Moist, fertile soil.
Propagation Methods:
Sow spore as soon as ripe.
Divide in spring. Pruning Methods:
In early spring cut back dead fronds.

Rainy Side Notes

This is the largest fern native to North America and is found along the western half of Oregon, Washington, and British Columbia. It grows as far south as California and Baja California, as well as in Nevada and Arizona.

Named after British botanist Thomas J. Woodward (1745-1820), a stand of Woodwardias would be a sight to see, reaching its ultimate height of 9 feet tall. Growing in the shadows of moist woodland, I imagine it would look like an ancient forest where dinosaurs roamed.

The soft green, long fronds and graceful shape of the fern is beautiful in the wild as well as the garden, where it will only reach five feet tall. The common name "giant chain fern" comes from the placement of the sori, which resembles links on a metal chain.

In Washington State where there is limited distribution of the plants, they are threatened by erosion and invasive species as well as collection of plants from the wild.


The Karok, Yurok and Tolowa tribes made leaf fiber pounded from the rachis, which was then woven into baskets. After processing the fibers, they dyed them using alder bark. The fibers were dried and rolled up until ready for use. They soaked the material fibers to make it pliable, which they used for weaving beautiful and useful baskets. Pomo and Kashaya tribes used the long fronds to line earth ovens for cooking acorn bread.

In the Garden

Woodwardias grow well in woodlands or next to streams, moist bogs, springs or ponds and even containers. If extra moisture is given during our Northwest drought period, this fern can even grow in full sun. The giant chain fern is not very frost tolerant, so grow in woodland or protected area. Do not fertilize, but give it a nice topping of compost, leaf mold or aged manure in fall.

Photographed in author's garden.

Rainy Side Gardeners —