Marsh Fern (Thelypteris palustris): Hardy Native Fern for Wet Soils

Overview

Marsh fern (Thelypteris palustris), also called eastern marsh fern or meadow fern, is a deciduous, rhizomatous fern native to wetlands across North America, Europe, and Asia. It thrives in saturated soils, making it invaluable for rain gardens, pond edges, and boggy areas.

Botanical Description

Fronds are pinnate-pinnatifid, 40–100 cm long, light green, arising singly from a long-creeping rhizome (not a tight crown). Pinnae are deeply lobed, with sori in rows near the midrib, protected by reniform indusia. The rhizome spreads steadily, forming loose colonies. Foliage dies back in winter.

Taxonomy

Family:	Thelypteridaceae
Genus:	Thelypteris (the-LIP-ter-is)
Species:	palustris (pal-US-triss)
Synonym:	Thelypteris thelypteroides

Growing Conditions

• Light: Part shade to full sun (if soil is constantly wet).
• Soil: Wet, acidic, organic; tolerates standing water.
• Moisture: High; requires consistently saturated soil.
• Hardiness: USDA zones 3–8.

Garden Uses

Perfect for rain gardens, bioswales, pond margins, and wet meadows. Combines with native iris, lobelia, swamp milkweed, and sedges. Spreads moderately; site where colonization is desired. Deer resistant.

Ecological Value

Provides cover and breeding habitat for amphibians and insects. Stabilizes wetland soils. A key component of native wetland plant communities. The specific epithet palustris means "of the marsh."