Onoclea sensibilis
L.
Sensitive Fern
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(c) Laura Clark, some rights reserved (CC BY), uploaded by Laura Clark
iNaturalist· cc-by-nc
(c) Deanna Frantz, some rights reserved (CC BY-NC), uploaded by Deanna Frantz
iNaturalist· cc-by
(c) Laura Clark, some rights reserved (CC BY), uploaded by Laura Clark
Description
Onoclea sensibilis is a deciduous Fern growing to 0.5 m (1ft 8in) by 0.5 m (1ft 8in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 4 and is not frost tender. The seeds ripen from June to October. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It can grow in full shade (deep woodland) or semi-shade (light woodland). It prefers moist or wet soil.
Edible Uses
The young uncurled leaves, often called 'fiddleheads', are used as a vegetable or eaten raw. Remove the brown scales and then steam the leaves in very little water. The young shoots have been sold as delicacies in Asian markets. Root - cooked. A famine food, it is only used in times of scarcity.
Medicinal Uses
Galactogogue Poultice Women's complaints. Sensitive fern has not been much used medicinally. However, one native North American Indian tribe did employ it quite widely to treat various women's complaints. An infusion of the root has been used to treat the pain following childbirth. A decoction of the roots has been used to treat fertility in women, to give strength after childbirth, to start the menses, and to treat swellings, cramps and a sore abdomen. An infusion of the whole plant, or just the root, has been applied externally to full breasts where the milk will not flow. A poultice of the plant is used in treating deep cuts.
Known Hazards
Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable. Many ferns also contain thiaminase, an enzyme that robs the body of its vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase.
Distribution
N. America - east of the Rockies to N.E. Asia.
Where It Grows
TEMPERATE ASIA: Amur, China (northeast), Hokkaidô, Honshu, Japan, Korea, Kurile Islands, Kyushu, Primorye, Sakhalin,Russian Federation. NORTHERN AMERICA: Canada, Québec, Nova Scotia, Ontario, Prince Edward Island, New Brunswick, Newfoundland and Labrador, Manitoba, United States, Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, Oklahoma, South Dakota, Wisconsin, Colorado, Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Texas,
Cultivation
Prefers a moist light soil in partial shade. Requires a damp humus-rich site in partial shade with preferably only 2 - 3 hours of sun daily. Plants require an abundance of water at the roots all year round and they grow well in a bog or woodland garden, or on the water's edge where they may grow out over the water. Requires a pH in the range 5 - 6.5. Plants can colonize most situations that are not too dry and are sheltered from harsh winds. A very hardy plant, the rootstock can tolerate temperatures down to about -30°c. Members of this genus are rarely if ever troubled by browsing deer. A very ornamental and easily grown fern, spreading quite vigorously by means of a slender far-creeping rhizome when it is established. It can become invasive in suitable conditions. The fronds die quickly with the first autumn frosts, which is why the plant has gained its common name of the sensitive fern.
Propagation
Spores - best sown as soon as they are ripe on the surface of a humus-rich sterilized soil. Keep the compost moist, preferably by putting a plastic bag over the pot. Pot on small clumps of plantlets as soon as they are large enough to handle and keep them in humid conditions until they are well established. Do not plant outside until the ferns are at least 2 years old. Division of underground rhizomes, October to March.
Other Uses
HairA decoction of the plant has been used as a hair wash to help prevent baldness. This species has a freely-running rootstock and makes an effective ground cover plant. Although it is deciduous its decomposing ferns make an effective weed suppressing mulch. Plants should be spaced about 1 metre apart each way.
