Saving a Rotting Dicksonia antarctica: Trunk Propagation Guide

A gardener in the Netherlands discovered the crown of a 2-meter Dicksonia antarctica (soft tree fern) had rotted after winter protection was removed. Experts suggested scooping out the rot and planting a young fern on the dead trunk—a known propagation method.

Step-by-Step Trunk Propagation

1. Assess viability: Cut into the trunk below the rot. If tissue is firm, greenish, and moist, the trunk is alive.
2. Remove rot: Scoop out all soft, brown, foul-smelling material until only clean, firm trunk remains.
3. Disinfect: Dust the cavity with horticultural fungicide (copper-based or sulfur) or cinnamon powder.
4. Prepare a juvenile fern: Obtain a small, healthy Dicksonia (or a offsets/pup from another plant).
5. Attach the young fern: Pack the cavity with moist, long-fiber sphagnum moss. Nestle the young fern's root ball into the moss, ensuring its crown sits at or slightly above the trunk's original soil line.
6. Secure & shelter: Wrap the trunk and new planting with horticultural fleece or burlap to maintain humidity. Stake if needed.
7. Maintain moisture: Mist the moss and crown daily. Keep the trunk damp but not waterlogged.
8. Monitor: New fronds should emerge in 4–8 weeks. Gradually reduce humidity once established.

Alternative: Basal Regeneration

If the trunk is dead to the base, cut it off at ground level. The root system may produce new shoots (called "crosiers") from the base. Mulch heavily and keep moist.

Reference

Australian National Botanic Gardens propagation guide: Dicksonia antarctica Propagation