Osmunda cinnamomea AGM

Cinnamon Fern Osmundaceae

Osmunda cinnamomea, the cinnamon fern, is a magnificent deciduous fern whose fertile fronds emerge in spring clothed in rich cinnamon-brown, rising from a handsome crown of pale green sterile fronds. There is a taxonomic wrinkle worth knowing: the species is now generally accepted by Kew as Osmundastrum cinnamomeum, although Osmunda cinnamomea remains widely used horticulturally, including by the RHS. Its enormous natural range extends across eastern North America, Central and South America and eastern Asia, including Japan, China, Taiwan and the eastern Himalaya. 

In cultivation it is remarkably accommodating provided it has moisture. Grow in fertile, humus-rich, preferably acidic soil in partial shade; it will tolerate surprisingly sunny positions if the roots never dry out. Boggy ground, pond margins and damp woodland are ideal. The cinnamon-coloured fertile fronds are produced separately from the sterile foliage, making this a fern with genuine seasonal theatre. RHS rates it H6, so cold is hardly its principal concern—dryness is.

Altitude: Sea level–2,300m
Hardiness: H6, approximately −20 to −15°C
Height: 1–1.5m
Spread: 0.5–1m