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OrnamentalfernStraightforward

Hart's tongue fern

Asplenium scolopendrium

The fern that is not fern-shaped: strap-like undivided glossy green blades in a shuttlecock, evergreen, and native to shady limestone. It grows out of walls and shaded steps where there is barely any soil at all, which is a position almost nothing else will take.

Position
Full shade or Dappled shade
Water
low demand
Drainage
Free-draining, Moisture-retentive
Grows to
35–60 cm × 35–60 cm
Hardiness
H6
Difficulty
Straightforward

August

Nothing to do

No sowing, planting, harvesting or pruning window falls in August.

Coming next month: plant.

Hart's tongue fern’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

ActivityJFMAMJJASOND
PlantMarch. April. September.
PruneMarch.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

Conditions it needs

Light
Full shade, Dappled shade
Frost
Very hardy
Hardiness rating
H6 (RHS)
Grows best at
6–22 °C
Soil
Chalky, Loam, Peat-free compost
Soil pH
6.5–8
Drainage
Free-draining, Moisture-retentive
Water needs
low
Drought
moderate tolerance
Waterlogging
poor tolerance
Heat
poor tolerance
Wind and exposure
poor tolerance
Where these figures come from
LightSourced guidancemoderate confidence
  • Royal Horticultural Society: Hart's tongue fern — position

Checked 2026-08-13

FrostSourced guidancehigh confidence
  • Royal Horticultural Society: Hart's tongue fern — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancemoderate confidence
  • Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atSourced guidancemoderate confidence
  • Royal Horticultural Society: Hart's tongue fern — temperature

Checked 2026-08-13

SoilSourced guidancemoderate confidence
  • Royal Horticultural Society: Hart's tongue fern — soil

Checked 2026-08-13

Soil pHSourced guidancemoderate confidence
  • Plant FinderMissouri Botanical Garden: Asplenium scolopendrium — culture

Checked 2026-08-13

DrainageSourced guidancemoderate confidence
  • Royal Horticultural Society: Hart's tongue fern — soil

Checked 2026-08-13

Water needsHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

DroughtHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

WaterloggingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

HeatHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

SoilVerdictWhy
Heavy clayWorks, with one conditionHart's tongue fern will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
SandyGrows well hereHart's tongue fern grows perfectly well on sandy without special measures, though it is not the soil it would choose.
Chalky and alkalineGrows well hereHart's tongue fern grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose.
LoamPrefers this soilLoam suits Hart's tongue fern as it stands: The pH suits it: it wants 6.5 to 8, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
SiltyPrefers this soilSilty suits Hart's tongue fern as it stands: The pH suits it: it wants 6.5 to 8, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering.
Peaty and acidWorks, with one conditionHart's tongue fern will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rockPrefers this soilShallow over rock suits Hart's tongue fern as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting.
Made ground and urban soilWorks, with one conditionHart's tongue fern will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height
35–60 cm
Mature spread
35–60 cm
Rooting depth
25 cm
Spacing
35–50 cm apart
Where these figures come from
Mature heightHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Mature spreadHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Rooting depthHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

SpacingSourced guidancemoderate confidence
  • Royal Horticultural Society: Hart's tongue fern — spacing

Checked 2026-08-13

How far apart to plant hart's tongue fernThree hart's tongue fern plants drawn in a row at their recorded spacing of 35–50 cm between plants. The spacing is drawn to scale against a one metre rule; the plants themselves are symbols rather than scale drawings, so the distance between them is the part to read.35–50 cmone metre
Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

Habit and ultimate size

What the plant becomes, rather than what it is when you buy it. The gap between the two is where most planting mistakes live.

Foliage
Evergreen
In a container
Good in a container long-term
Where these figures come from
FoliageSourced guidancehigh confidence
  • Royal Horticultural Society: Asplenium scolopendrium — foliage

Checked 2026-08-13

In a containerHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

MethodSuitabilityWhat it needs
Open groundWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

Traditional dug bedWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

Raised bedWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

ContainerWell suited
source

Sourced guidancemoderate confidence

  • Royal Horticultural Society: Growing method suitability

Checked 2026-08-13

Growing it

  • PlantingOne of the few ferns that positively prefers alkaline ground, and it will establish in the mortar joints of a shaded wall or between shady paving with almost no soil. That makes it the answer to a north-facing basement area or a dark passageway where nothing else takes.
  • PruningRemove old and tattered fronds individually in early spring. Evergreen, so the crown should never be sheared.
Where this guidance comes from
PlantingSourced guidancehigh confidence
  • Royal Horticultural Society: Asplenium scolopendrium — position

Checked 2026-08-13

PruningSourced guidancemoderate confidence
  • Royal Horticultural Society: Asplenium — care

Checked 2026-08-13

Where to make a pruning cutFour stems compared. The first is cut cleanly on a slope about five millimetres above an outward-facing bud, sloping away from it, and is labelled correct. The second is cut too far above the bud, leaving a long stub that dies back. The third is cut too close, into the bud itself, which loses the shoot. The fourth is cut sloping towards the bud so rain runs onto it rather than away, which rots it. In every case the bud points outwards, away from the centre of the plant.Correct5 mm, sloping awayToo highstub dies backToo closebud lostSloping inrain sits on the bud
The bud you cut to becomes the new shoot, and it grows in the direction it points — which is why an outward-facing bud opens the plant up and an inward-facing one crosses the middle.

Sources for this page

GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.