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Common Name: Sensitive Fern

General Information

Onoclea sensibilis is a

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[].

Botanical References

, ,

Range

N. America - east of the Rockies to N.E. Asia.

Habitat

Open swamps, thickets, marshes, or low woods, in sunny or shaded locations, often forming thick stands from sea level to elevations of 1500 metres[],

Properties

Edibility Rating
Medicinal Rating
Habit	Deciduous Fern
Height	0.50 m
Growth Rate	Fast

Cultivation Details

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[].

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

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[].

Other Uses

A 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[].

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.