Thelypteris kunthii
 
Common Names Southern Shield Fern, River Fern, Kunth’s Maiden Fern
 
Zones 7A–10B
 
A fast-spreading, semi-evergreen fern native to the southeastern U.S., Mexico, and the Caribbean, Thelypteris kunthii thrives in moist woodlands, streambanks, and shaded wetlands. Its arching, finely textured fronds and tolerance for heavy shade make it a favorite for naturalistic plantings and restoration projects. Often called River Fern in Texas and Southern Shield Fern in Florida, it forms lush colonies that suppress weeds and stabilize soil.
 
Key Features
Growth Habit: Rhizomatous; spreads to form dense colonies
Height: Typically 2–4 ft (0.6–1.2 m); spread 2–4 ft
Fronds: Arching, triangular, bright green; pinnate-pinnatifid; hairy on both surfaces
Stems: Green; short creeping rhizomes; non-aromatic
Reproduction: Spores borne in rounded indusia along midvein of pinna lobes; no flowers or fruit
Ecology: Provides cover for amphibians and small wildlife; supports shade-tolerant insect diversity; deer resistant
 
Growing Conditions
Light: Deep shade to dappled sun
Watering: Moderate to high; prefers moist soils but tolerates brief drought
Soil: Loam, clay, or sandy; humus-rich; tolerates poor drainage
Temperature: Hardy to ~0°F (–18°C); dies back in hard freezes
Humidity: High tolerance; thrives in woodland humidity
Propagation: Division or spores; spreads readily by rhizomes
Tolerance: Heavy shade, seasonal flooding, deer browsing
 
Landscape Use Ideal for woodland edges, shaded wetland restorations, and native groundcover beds. Use in mass plantings or as a backdrop for spring ephemerals. Pairs well with Osmunda regalis, Asarum canadense, and Carex blanda.