Ornamental · Aspleniaceae
Hart's Tongue Fern
Asplenium scolopendrium
Give it deep shade, steady moisture, and a touch of lime, and this glossy strap-leaved fern brings evergreen calm to a room all winter.
Full shade
Every 5–10 days
USDA 5–9
12–18 in · 30–46 cm
Overview
The hart's tongue fern is the quiet sophisticate of the shade garden, a plant that earns its place through composure rather than flash. Where other ferns fan out in lacy, feathery layers, this one keeps things clean and architectural, its long undivided straps rising from a tight central crown into a tidy shuttlecock. That restraint is exactly what makes it feel considered in a planting or a pot.
It hails from the spleenwort family and grows wild across Europe on shaded limestone walls, rocky banks, and cave mouths, and that heritage shapes where it belongs in a home. Set it in cool shade with a sweet alkaline soil and steady moisture, and it settles into a north-facing corner or a shaded courtyard the way a good armchair settles into a reading nook. Because it stays evergreen, it keeps a room or a border furnished straight through winter.
This is a slow companion for the long view, not a quick seasonal fix. Pair it with a shaded doorway, a stone trough, or a dim spot under trees, and it lends a corner a grounded, structural presence that flatters the space and the rhythm of the day around it.
Care
The short version: style it into full to partial shade, keep the soil evenly moist yet sharply drained, choose a sweet alkaline mix with a little lime, and give it the higher humidity it knew on shaded rock.
Light
Think of this as a plant for the shaded corners a room or garden usually struggles to fill. It wants full to partial shade, the dappled or deep cover found under trees or against a north wall. Keep it clear of hot afternoon sun, which scorches the fronds and undoes the look.
Water
Keep the soil evenly moist but never waterlogged, watering every 5 to 10 days and a touch more through a dry spell or the first season in its new spot. Drainage is the quiet essential, since it dislikes standing water as much as drought, so a moist, sharply drained soil keeps it looking its best.
Soil
Settle it into humus-rich, well-drained soil on the alkaline side, ideally a pH between 6.5 and 8.0. It is one of the rare ferns that takes to lime, so a chalky or limestone-rich mix suits it where fussier plants would falter.
Temperature
It is admirably cold-hardy, weathering winter lows to -20°F (-29°C) and summer warmth to about 75°F (24°C). That range is why it stays evergreen across zones 5 to 9 and keeps a corner furnished rather than bare.
Humidity
Having grown up on shaded rock and cave mouths, it favors air on the damp side, around 50% to 80%. In a dry room or an exposed bed the frond tips brown, so group it with other plants or place it where the air stays still and moist.
Feeding
Ferns are light feeders, so a gentle hand keeps things tasteful. One drink of diluted, balanced liquid fertilizer in spring is enough, and overfeeding only detracts.
Pruning
Upkeep is minimal, which is part of its appeal. Remove dead or damaged fronds as you notice them, and cut back the tatty, winter-burned old fronds in late winter, just before the new croziers unfurl.
Repotting
A potted plant asks for a fresh home only every 2 to 3 years, or sooner if roots push through the drainage holes, the crown crowds up, or water runs straight through. Move it into a slightly larger pot with fresh, lime-rich, gritty mix.
Size & spacing
It stays compact and grows slowly, reaching about 12 to 18 inches (30 to 46 cm) tall and roughly the same across, an easy scale for a trough or a shaded bed. Allow each plant 12 to 18 inches (30 to 46 cm) of room so the crowns can settle into their full rosette.
When to plant
This fern is hardy and unhurried, which suits a planting you mean to keep. Sow ripe spores indoors in spring to raise your own, and settle young plants into their place outdoors in spring once hard frost has passed. It stays evergreen in zones 5 through 9, so an established planting furnishes its corner year-round rather than dying back to the ground.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Sow ripe spores indoors in spring at about 15°C (60°F)
- Plant: Spring, after the danger of hard frost has passed
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Most of what unsettles this fern comes down to water and light rather than pests. Wet roots and harsh sun account for nearly all of it. Match what you notice below, then ease the conditions before the display suffers.
Fronds slumping while the roots darken and soften
When a display starts to slump, the culprit is usually root rot born of soil that stayed too wet, not a passing illness. Ease the plant from its spot and the story is clear: the failing roots feel soft and smell sour where healthy ones would be firm and pale. Pare away the rot, put the drainage right, and reset it into a gritty, lime-rich mix so the crown can hold its poise again.
Fix:
- Improve drainage immediately
- Reduce watering frequency
- Repot into a gritty, well-drained, lime-rich mix and trim away rotted roots
Scorched brown tips and edges spoiling the look
Brown, brittle edges signal sun scorch, often with dry air or thirsty soil playing a supporting part. The tell is where it lands: the side turned to the sun suffers while the fronds in shade keep their calm green. Shift the planting into a softer, shadier corner, lift the humidity nearby, and hold the soil evenly moist to bring the display back.
Fix:
- Move to a shadier spot
- Raise humidity around the plant
- Keep soil evenly moist
Older fronds fading and fraying by winter's end
A little wear by late winter is simply winter burn on the oldest outer fronds, the toll that cold and drying wind take on an evergreen. The look is untidy for a season, yet the heart of the plant stays sound and refreshes itself when spring returns. Tidy the worn fronds away in late winter, before the new croziers begin to unfurl.
Fix:
- Cut back damaged fronds in late winter before new croziers unfurl
Toxicity
For a home shared with pets and children, this fern is a reassuring choice: it is safe. As a true fern it carries no known toxin, so cats, dogs, and grazing animals can share its corner without risk. The one thing to keep in mind is mechanical, since the fronds and spores can scratch or irritate sensitive skin, so wash your hands after handling it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A cat can share the room with this fern in complete safety, with no toxic risk in play. An idle nibble might bring the passing stomach upset any greenery could, and no more than that.
Dogs None
For a household dog there is nothing poisonous to fear. A chewed frond may prompt a little drool or a brief pause in appetite from the roughage, though the plant does no real harm.
Horses None
Horses can graze beside it with ease, since a true fern of this kind holds no toxin that would ever trouble them.
Rabbits None
A rabbit may browse the fronds without any harm. Let it feature as one part of a varied diet rather than the whole plate.
Livestock None
Cattle, goats, and sheep come to no poisoning from this fern and can keep it company in a shaded paddock.
Birds None
Birds remain out of danger around the plant, whether they settle among the fronds or pick at one in passing.
People None
The fern is safe to keep and to raise around children. The single note worth minding is mechanical: the fronds and spores can scratch or irritate sensitive skin, so wash your hands once the pruning is done.
Fronds and spores may cause mild mechanical irritation in sensitive individuals; wash hands after handling.
Varieties
Beyond the plain species, a small cast of selections is prized for the way their fronds twist, ripple, and flare. These are the forms worth folding into a scheme.
'Crispum'
A prized garden form whose strap-shaped fronds carry margins frilled and crisped into tight, decorative waves.
'Undulatum'
It is defined by pronounced wavy edges that ripple along the whole length of each blade.
'Angustatum'
It reads slimmer than the type, wearing narrower, more strap-like fronds than the plain species.
'Sagittatum'
It is marked by a frond base that opens into a distinct arrow- or fishtail-shaped set of lobes.
var. americanum (American hart's-tongue fern)
A rare North American native of limestone sinkholes and federally protected, so it is not the form you will meet in a garden center.
How to propagate
You can build up a planting of this fern two ways: split an established clump for quick results, or take the slow route from spores.
DivisionModerate
Late winter to early spring · 2-3 months for divisions; spore-grown plants take 1-2+ years to reach garden size
The graceful shortcut is division in late winter to early spring. Lift a settled clump that has built several crowns, part it into pieces, and each one takes hold over two to three months. For the patient gardener there is also spore raising, sown on the surface of a sterile mix as the spores ripen and held at about 60°F (15°C), a slow path where a spore-grown plant needs one to two years or more to reach garden size.
Myths
Because its fronds are undivided and strap-like, it is not a real fern.
It is a true fern in every sense. It reproduces by spores, arranged in neat herringbone rows beneath the fronds, even though the leaves never open into the lacy silhouette most people picture.
Hart's tongue fern is endangered and illegal to grow.
The widespread European species is common and sold freely for the garden. Only the North American native variety, var. americanum, is rare and legally protected, and that is not the plant waiting on the nursery bench.