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Hart's tongue fern

Asplenium scolopendrium, Aspleniaceae

Sources last read 14 September 2026.

Not yet rated How forgiving it is has not been judged here yet.

Also called burnt weed, buttonhole, Christ's hair, Hart's tonguefern, Hart's-tongue, hartstonque and horse tongue.

Hart's tongue fern (Asplenium scolopendrium), the whole plant.
Ivan Medenica, CC BY-SA 4.0 · Wikimedia Commons

Toxicity is partly unassessed

  • Not assessed for cats. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
  • Not assessed for dogs. This plant is not on the ASPCA list. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.
  • Not assessed for people. RHS publishes no harm statement for this plant. That is not a finding of safety: none of the sources read for this site gives an answer either way. Treat it as unknown.

What the sources say about its care

Sources file this plant under other names: Asplenium scolopendrium AGM. Citations below point at the name its source uses.

Light
Full shade, Partial shade
RHS · read 13 September 2026
Water
Moist but well-drained
RHS · read 13 September 2026
Humidity

No source read publishes a humidity figure for any plant on this site. What follows is general guidance for foliage plants.

ASHRAE recommends indoor relative humidity between 30% and 60% 30–60%
Penn State Extension · read 13 September 2026
Temperature

How cold this tolerates, not what it prefers. No source read for this site publishes a preferred range for a plant indoors.

H6 — -20 to -15°C -20 to -15 °C
RHS · read 13 September 2026
Soil
Chalk, Clay, Loam, Sand; pH Alkaline or Neutral
RHS · read 13 September 2026
Toxic to cats
Not on the ASPCA list. That is not a finding of safety.
ASPCA · read 13 September 2026
Toxic to dogs
Not on the ASPCA list. That is not a finding of safety.
ASPCA · read 13 September 2026
Harmful to people
No statement of harm to people is published for this plant; that absence is not evidence it is safe.
RHS · read 13 September 2026

Routine care

Watering
Copes with dry shade, but water it regularly in its first season and apply a thick mulch.
RHS · read 13 September 2026
Propagation
Increase by division, or sow spores at 15°C once ripe.
RHS · read 13 September 2026
Pruning
Remove dead or damaged fronds when needed.
RHS · read 13 September 2026
Pests and diseases
Usually free of pests outdoors. Diseases: a rust can occur in damp, mild winters.
RHS · read 13 September 2026

Move something and watch

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Close view of Hart's tongue fern (Asplenium scolopendrium) foliage.
Close upDidierFy, CC BY-SA 4.0 · Wikimedia Commons
Hart's tongue fern (Asplenium scolopendrium) growing wild.
In the wildKrzysztof Ziarnek, Kenraiz, CC BY-SA 4.0 · Wikimedia Commons

About the plant

Asplenium scolopendrium, commonly known as the hart's-tongue fern, is an evergreen fern in the family Aspleniaceae native to the Northern Hemisphere.

From Wikipedia, CC BY-SA 4.0 · read 13 September 2026

Native range
Temp. Northern Hemisphere to Mexico and N. Africa
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Temp. N. Hemis.
RHS · read 13 September 2026
Climate
temperate
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Growth form
perennial or rhizomatous geophyte
World Checklist of Vascular Plants, June 2026 release, CC BY.
Kew WCVP · read 13 September 2026
Tufted (evergreen)
RHS · read 13 September 2026
Size
Height 0.1-0.5 metres; spread 0.1-0.5 metres after 5–10 years
RHS · read 13 September 2026

Other Asplenium

More of the Aspleniaceae family

Plants with similar care

Sources

What this does not cover

The figures above are what published sources say, not measurements of the plant in your room. They say nothing about your pot size, your water, the season, or how far from the glass the plant stands, and those decide more than any figure here does.

Humidity has no species figure because no source read for this site publishes one, and the only temperature published for this plant is a cold floor. The simulator fills those gaps with general figures for its kind of plant, marked as general and listed on how we read sources. Where a toxicity row says the plant was not assessed, that is the absence of a finding and not a finding of safety.

If something is already wrong, the diagnosis tool asks about the soil, the window and the watering, which is where the answer usually is.