Southern Sword Fern (Nephrolepis cordifolia): Tough, Spreading Fern for Warm Climates

Overview

The southern sword fern (Nephrolepis cordifolia), also called tuberous sword fern or ladder fern, is a vigorous, evergreen fern native to tropical and subtropical regions worldwide. Its upright to arching, once-pinnate fronds reach 2–3 feet, rising from scaly rhizomes that produce distinctive round tubers (hence "tuberous"). It spreads aggressively to form dense colonies, making it a effective groundcover—but potentially invasive in warm, moist climates.

Uses & Cautions

• Erosion Control: Dense roots stabilize slopes in frost-free areas.
• Container Plant: Popular for hanging baskets and porch pots.
• Invasive Potential: Listed as invasive in Florida, Hawaii, and other warm regions. Check local regulations before planting in the ground.

Culture

Full sun to deep shade (best in filtered light). Adaptable to various soils if moist. Drought tolerant once established. Tubers store water, aiding survival. USDA zones 9–11 outdoors; elsewhere as annual or houseplant.

Taxonomic Profile

Tough and lush, southern sword fern is a workhorse—but plant responsibly where it can't escape.