United States / Grow / hard treefern

hard treefern (Dicksonia squarrosa)
Photo: (c) Saryu Mae 前 朝琉, some rights reserved (CC BY) (CC BY), via iNaturalist. Species-typical, not necessarily this cultivar.

hard treefern

Dicksonia squarrosa · Dicksoniaceae · all Dicksonia records · also called Wheki, Rough tree fern · Wikipedia

View Saved

Is this one for your yard?

Enter your ZIP to see whether this is legal to plant in your state, and whether it survives your winter.

Dicksonia squarrosa enters through the 60-species shoot-flammability assessment, the laboratory lineage accepted for this record. For this tree fern, limited evidence on the evidence table accompanies an avoid direction computed from the accepted rows.

Same-form alternatives are cited under related plants, making that comparison more useful than reading the direction alone. The genus page gathers other records in the genus without transferring their findings here. Together, those routes keep this tree fern's sparse pack, computed result, and comparison set visibly separate. For a source-first reading, return to the evidence table before exploring those alternatives.

Fire-resistant perennials instead

Form
perennial
Region
New Zealand
Rated in
Global; New Zealand
On this lot

1. Fire evidence and conditions

Fire evidence
Highly flammable — location does not change the cited classification.
Evidence regions
Global; New Zealand

2. Why this plant is relevant here

3. Legal, ecological, and broader status

How to read this page

The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.

The evidence

Grouped by what each source concluded. Primary evidence rated the plant itself (a lab, field program, or original curation); corroboration compiled or republished another source's rating and resolves to its root lineage.

Avoids (1)

Mid-scale / conditional (1)

Listed without a rating (14)
Corroboration (14 rows from 1 source)
  • FLAMITS: FLAMmability plant traiTS database — Dryad / Global Ecology and Biogeography · Dryad version 9 · original source Corroboration Trait database lineage: meta-aggregator

    14 cited rows from this source; its identity, lineage and tier are stated once.

    • Primary study Cui2020a: Cui, X., Paterson, A. M., Wyse, S. V., Alam, M. A., Maurin, K. J. L., Pieper, R., ... Curran, T. J. (2020a). Shoot flammability of vascular plants is phylogenetically conserved and related to habitat fire-proneness and growth form. Nature Plants, 6, 355-359.

      Shared row context: plant part branches; fuel all; predrying yes; device grill; site Cui2020a-1; sampling ND.

      • “ignition frequency (%): 100”

        FLAMITS record 1380; Ignitability measurement.

      • “maximum sample temperature (°C): 606.3”

        FLAMITS record 1574; Combustibility measurement.

      • “burning duration (s): 21.5”

        FLAMITS record 1768; Sustainability measurement.

      • “estimated burnt biomass (%): 55”

        FLAMITS record 1962; Consumability measurement.

    • Primary study Mason2016: Mason, N. W. H., Frazao, C., Buxton, R. P., & Richardson, S. J. (2016). Fire form and function: evidence for exaptive flammability in the New Zealand flora. Plant Ecology, 217, 645-659.

      Shared row context: plant part leaves; fuel live; predrying yes; device muffle furnace; site Mason2016-5; sampling summer.

      • Shared measurement context: Ignitability measurement.

        • “temperature at smoke (°C): 145.84”

          FLAMITS record 8371.

        • “temperature at smoke (°C): 141.51”

          FLAMITS record 8372.

        • “temperature at flaming (°C): 283.26”

          FLAMITS record 8586.

        • “temperature at flaming (°C): 235.59”

          FLAMITS record 8587.

      • Shared measurement context: Combustibility measurement.

        • “temperature increase rate (°C/s): 16.7”

          FLAMITS record 8801.

        • “temperature increase rate (°C/s): 16.87”

          FLAMITS record 8802.

    • Primary study Wyse2016: Wyse, S. V., Perry, G. L. W., O'Connell, D. M., Holland, P. S., Wright, M. J., Hosted, C. L., ... Curran, T. J. (2016). A quantitative assessment of shoot flammability for 60 tree and shrub species supports rankings based on expert opinion. International Journal of Wildland Fire, 25, 466-477.

      Shared row context: plant part branches; fuel all; predrying yes; device grill; site Wyse2016-1; sampling ND.

      • “ignition frequency (%): 100”

        FLAMITS record 14336; Ignitability measurement.

      • “maximum sample temperature (°C): 606.3”

        FLAMITS record 14396; Combustibility measurement.

      • “burning duration (s): 21.5”

        FLAMITS record 14456; Sustainability measurement.

      • “estimated burnt biomass (%): 55”

        FLAMITS record 14516; Consumability measurement.

Fire-resistant perennials instead

Fire-resistant perennials listed above

Last verified 2026-08-23. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata · Wikipedia · ITIS

Dicksonia squarrosa (Wheki, Rough tree fern). FireApproved. https://fireapproved.com/plants/dicksonia-squarrosa/. Last verified 2026-08-23.