Environment

Tuber ladder fern

Tuber ladder fern.Tuber ladder fern. 

Common names:
Tuber ladder fern, Chinese ladder fern, tuber sword fern, Boston fern

 

Scientific name:
Nephrolepis cordifolia

 

Regional classification:
Common pest plant - education only

 

National classification:
National Pest Plant Accord – banned from being sold, propagated or distributed

Description

A terrestrial or epiphytic fern that grows to one metre in height, with rhizomes and producing many long runners. Tuber ladder ferns have round, 1-3cm hairy potato-like tubers. This is the only fern with tubers.

 

Leaves:

  • fronds are 40-100 x 5-8cm
  • erect and arching when long
  • with serrated leaflets

Tuber ladder ferns spread by spores, runners and tubers.

 

Dense, long-lived patches are formed, often spreading to cover large areas. It grows in damp or dry, on ground or trees, in the open or shady spots. It can grow in most soil types, and in hot to mid-cool temperatures.

 

There is a similar native ladder fern, but it has no tubers and is rare. It is found in geothermal sites and on Raoul Island.

 

Another similar fern, also called Boston ladder fern, is an indoor plant species, and is not known to be weedy. These have wider, softer fronds and no tubers.

Why is it a problem?

Tuber ladder fern crowds out groundcovers, shrubs and other ferns. It can contribute to streamside erosion.

 

It invades disturbed bush and shrubland, fernalnd, tussockland, coastal forest, streamsides and gumlands.

 

Runners and tubers quickly spread from dumped vegetation and soil, occasionally through flooding. Runners and tubers will both resprout if not disposed of carefully.

What can I do?

This is usually mistaken for a native plant, so it is good for people to understand that it is an unwanted pest plant.

Recommended control methods


Site management:

  • Often mistaken for a native plant.
  • Easy to kill.
  • Leave treated sites 3-4 months to kill tubers before clearing or replanting.

Recommended approaches:

  1. Dig out taking care to remove all tubers.
  2. Weed wipe (2g metsulfuron/1L)
  3. Spray (1g metsulfuron/10L).

Disposal:

  • Mulch foliage.
  • Dispose of tubers & runners.

Caution: When using any herbicide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.

More information

For further information or control advice please contact one of our Biosecurity Officers at the Northland Regional Council on 0800 002 004:

  • Whangarei: Ken Massey
  • Dargaville: Peter Joynt
  • Kaitaia: Doug Foster

 

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