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Todea spp.
king fern
Australia, New Zealand, southern Africa, and New Guinea
Overview
Todea spp. is a genus of two species of large evergreen ferns in the family Osmundaceae, the royal fern family. T. barbara, the king fern, occurs in Australia, New Zealand, and southern Africa, while T. papuana is confined to New Guinea. Plants build a massive, fibrous rootstock that thickens over decades into a short, trunk-like caudex, sometimes more than 3 feet (1 m) across and able to carry many crowns at once. The fronds are bipinnate, leathery, and dark green, arching to 3-8 feet (0.9-2.5 m) long in a dense shuttlecock. Unlike the related Osmunda spp., the spore-bearing tissue sits on the underside of ordinary green fronds rather than on separate fertile fronds. Growth is slow, and large clumps in the wild are estimated to be many decades to centuries old. The genus grows in shaded, constantly moist gullies and along streambanks on acidic soils. It needs year-round humidity and shelter, and old plants are hard to lift or divide because the woody caudex is dense and slow to regenerate. Frost tolerance is limited to light, occasional cold.
Native Range
Native to the Southern Hemisphere, with T. barbara found in eastern and southern Australia, New Zealand, and southern Africa, and T. papuana restricted to the mountains of New Guinea.Suggested Uses
Grown in shaded fern gardens, damp gullies, and large containers or conservatories in frost-prone areas. The trunk-forming habit suits it to sheltered, woodland-style plantings beside water.How to Identify
Appearance
Size & Dimensions
Height3' - 8'
Width/Spread3' - 6'
Bloom Information
Ferns do not flower. Spores ripen on the underside of the green fronds through the warmer months and are shed as a green dust that is short-lived and must germinate quickly. New fronds unfurl from the crown in spring.
Detailed Descriptions
Foliage Description
dark greenGrowing Conditions
Sun Requirements
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Plants grow in part to full shade in acidic, humus-rich soil kept constantly moist, with a pH near 5.0 to 6.5. High humidity and shelter from drying wind are needed, and the rootstock must never dry out fully. Growth is slow, and a sizeable trunk takes many years to form. Established plants tolerate light frost but are damaged by hard freezes, limiting outdoor culture to zones 8 to 10. Spores are the usual means of increase, as the woody caudex divides poorly. Feeding is light, matching the lean, leaf-littered soils of its native gullies.Pruning
Pruning is limited to removing old fronds once they brown, cutting them close to the crown. The fibrous trunk is not cut. Tidying is done in spring as new fronds emerge.Container Growing
✓ Suitable for container growing
Minimum container size: 10 gallons