Rumohra adiantiformis aka Iron Fern

Rumohra adiantiformis is an evergreen fern called leather fern or leatherleaf fern. Its native range includes southern Africa, Australia, and central South America. It also grows naturally in the Caribbean and Madagascar. Kew links it with wet tropical climates. Plants can grow in soil or live as epiphytes. In cultivation, it suits shaded gardens, pots, and sheltered spaces under glass.

The plant forms leafy clumps and spreads through creeping rhizomes. Garden plants reach about 3 feet [0.91 metres] tall. Reported mature spread ranges from 3.3–5 feet [1–1.52 metres]. RHS gives an upper height of 3.3 feet [1 metre]. Its glossy, dark green fronds have a firm, leathery feel. They have a triangular to oval outline. Each frond divides into two or three levels of leaflets. Fronds can reach 2.5 feet [0.76 metres] long. Their width can reach 0.67 feet [0.20 metres]. This fern does not flower; growers can raise it from spores.

Choose partial shade or full shade for garden planting. Use rich soil with plenty of humus and good drainage. Keep the soil evenly moist rather than waterlogged. RHS lists sandy and loamy soils with acid or neutral pH. It also calls for a sheltered site. Missouri Botanical Garden gives USDA hardiness zones 8–11. RHS rates it H3, suited to mild or coastal UK areas. The two ratings describe different regional growing conditions.

Under glass, grow it on bark or in shallow pots. Hanging baskets also suit this fern. RHS suggests orchid compost, or peat-free compost with extra grit. Water and mist it during active growth. Give less water in winter. Feed monthly during growth with a half-strength liquid fertiliser. Propagate by dividing rooted rhizomes or sowing spores. Sow spores on the compost surface at 21°C. RHS gives two to five years to reach maturity.

Use this fern beneath trees, around foundations, or in woodland gardens. It also provides ground cover in shade gardens. Growers cut its fronds for bouquets, corsages, and other arrangements. The cut foliage can last about two weeks in water. Missouri Botanical Garden reports tolerance of deer and heavy shade. It lists low maintenance needs and no known pest or disease problems. RHS also reports few pest or disease concerns. No routine pruning is needed.