Overview
Osmunda claytoniana is a fern in the genus Osmunda, part of the Osmundaceae family. It typically grows around 0.5 m tall. Osmunda claytoniana grows best in full sun, and tolerates most soils and acidic to neutral pH. Its UK hardiness is rated H7. Suggested uses include shade gardens, woodland gardens and naturalized areas. It is native to North America and Asia.
About
Osmunda claytoniana is a fern commonly known as the interrupted fern. It typically reaches about 0.5 m and produces fronds through spring and summer. It grows in moist to wet soils that are acidic to neutral and will tolerate sandy, loamy or clay textures. It is fully hardy (H7) in the UK.
Wikipedia contributors, CC BY-SA 4.0 — Claytosmunda
About the genus
Osmunda is a genus of primarily temperate-zone ferns of family Osmundaceae. Five to ten species have been listed for this genus. They have existed since the Early Cretaceous.
Wikipedia contributors, "Osmunda", CC BY-SA 4.0 — Osmunda
In the garden
A member of the Osmundaceae, Osmunda claytoniana comes from parts of North America and Asia and is sold under the common name interrupted fern. Plants produce their fronds in spring and retain foliage into summer, providing seasonal cover in shady places. Mature clumps remain relatively low, reaching around 0.5 m. Site selection should favour moisture: this fern tolerates wet ground and prefers moist but well-drained soils. It adapts to a range of soil textures — sandy, loamy or clay — within an acidic to neutral pH. Light requirements cover full sun through partial shade, though exposure listings commonly recommend partial shade in established plantings. It is fully hardy in the UK (H7) and, in USDA terms, fits zones 3–7. Use Osmunda claytoniana in shade gardens, woodland borders or naturalised areas where a spring-to-summer fern layer is wanted. Grouping several plants will create a low, leafy understorey beneath taller shrubs or trees. Because the seasonal fronds are the feature, siting it where they are easily seen from paths or seating makes the most of its seasonal presence.
Growing conditions
Best soil and position for Osmunda
- Sunlight
- Full sun
- Soil type
- Sandy, Loamy, Clay
- Soil pH
- Acidic to neutral
- Soil moisture
- Moist but well-drained, Wet
- Exposure
- Partial shade
- UK hardiness
- H7
Plant details
Osmunda claytoniana size, habit and characteristics
- Plant type
- Fern
- Height
- 0.5 m
- Suggested uses
- Shade gardens, woodland gardens, naturalized areas
- Native to
- North America, Asia
Care notes
Pruning and caring for Osmunda claytoniana
- Cultivation
- Prefers moist, humus-rich soil; avoid dry conditions; tolerates some sun if soil is moist
- Pruning
- Remove dead or damaged fronds in early spring
- Propagation
- Spores, division
Frequently asked questions
How do I grow Osmunda claytoniana?
Prefers moist, humus-rich soil; avoid dry conditions; tolerates some sun if soil is moist.
Where is the best place to plant Osmunda claytoniana?
Osmunda claytoniana prefers full sun. It suits partial shade positions.
What soil does Osmunda claytoniana need?
Osmunda claytoniana is adaptable and grows happily in most soil types, including sandy, loamy and clay. It prefers acidic to neutral soil. Aim for soil that stays moist but well-drained to wet.
How do I prune Osmunda claytoniana?
Remove dead or damaged fronds in early spring.
How big does Osmunda claytoniana grow?
Osmunda claytoniana reaches a height of 0.5 m.
Is Osmunda claytoniana hardy in the UK?
Osmunda claytoniana has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Osmunda claytoniana?
Spores, division.
More in the Osmunda genus
- Osmunda cinnamomeacinnamon fern
- Osmunda lancea
- Osmunda regalis 'Cristata'royal fern 'Cristata'
- Osmunda regalis var. gracilisRoyal Fern
