Hart’s-tongue fern

Hart’s-tongue fern: how do you recognise it?

Habit

Loose rosette of fronds, 30–50 cm tall and up to 60 cm wide.

Fronds

Undivided, strap- to tongue-shaped, 20–50 cm long, glossy bright green, with a heart-shaped base. Evergreen.

Spores

On the underside the spore clusters form slanting, parallel lines on either side of the midrib.

Young croziers

In April–May the new fronds unfurl from pale green croziers with small brown scales.

Roots

Short rhizome with dense, fibrous roots that even fit into narrow cracks between stones.

Plants: March–May and September–October · Pruning: March

Why grow it?

• Evergreen: the glossy fronds brighten the shade even in winter.
• A very unusual frond shape that contrasts beautifully with finely divided ferns.
• Happy between stones, at the foot of a wall or in a shady rock garden.
• Likes lime, which many other ferns struggle with.
• Compact, so suitable for small gardens and pots.

Hart’s-tongue fern: where does it grow best?

• Partial or full shade; in sun the fronds scorch.
• Neutral to chalky soil: sand, loam or clay, humus-rich and well drained. It likes growing between stones or against a wall with lime mortar.
• Normally moist soil, neither dried out nor waterlogged; humid air suits it.
• Sheltered from cold wind and strong winter sun.
• Allow 40–50 cm between plants.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Neutral or chalky

Moisture

Normal

Size

0.5 m tall, 0.6 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Hellebore: Flowers in winter and also likes lime and shade.
• Snowdrop: White bells in February among the green fronds.
• Barrenwort: Dainty spring flowers and a tough ground cover for shade.
• Sweet woodruff: A low, fresh green carpet with small white flowers around the base.
• Male fern: Finely divided fronds as a contrast with the undivided tongues.

Hart’s-tongue fern: when and how to plant it?

Plant in March–May and September–October.

1. Plant from March to May or in September–October, when the soil is not frozen or waterlogged.
2. Dig a hole twice as wide as the pot and mix in some leaf mould; on acid soil add some limestone chippings too.
3. Set the plant at the same depth as in the pot: the crown must stay above the soil, or it will rot.
4. Between stones, fill the crack with a mix of garden soil, compost and coarse sand.
5. Water generously straight away and keep the soil slightly moist for the first few months.
6. A thin layer of leaf mould around the plant keeps the soil cool.

Care

Watering

In dry spells during the first year. After that only in long dry periods.

Feeding

Not needed; a little leaf mould in spring is enough.

Old fronds

In March cut off brown and damaged fronds.

In a pot

Use free-draining compost mixed with coarse sand and keep the pot in shade.

Dividing

Every few years, when the clump becomes too large or crowded, in spring.

Tip: Plant it between stones or at the foot of a shady wall: there it finds the lime and the cool, moist spot it looks for. In March only cut away the damaged old fronds.

Hart’s-tongue fern: when to prune it?

Pruning months: March.

When: In March, before the new croziers unfurl. The fronds stay green, so only cut what looks untidy.

How:

• Cut brown, withered and winter-damaged fronds off at the base.
• Leave healthy green fronds: they decorate the plant until the new ones are fully grown.
• Watch out for the young croziers in the crown: do not cut into them.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April: dig up an older clump with several crowns and split it into pieces, each with a crown and roots. Replant at once.

Spores

In late summer or autumn collect ripe spores and sow them on moist, sterile compost under glass. On damp walls it also self-seeds.

Hart’s-tongue fern: how does it get through the winter?

Hardy to −25 °C.

• Hardy to about −25 °C: no protection is needed in Belgium.
• The fronds stay green all winter; in hard frost they may lie flat and get brown patches.
• A sheltered spot against a wall protects it from cold wind and strong winter sun.
• In a pot: stand the pot in a sheltered spot and keep the soil slightly moist, but not wet.

Diseases and pests

• Brown lines under the fronds: These are the spore clusters, not a disease or pest. Nothing needs doing.
• Scorched fronds: Brown, dry patches from too much sun or drought. Water and choose a shadier spot.
• Frost damage: After hard frost or cold wind the fronds get brown edges. Cut them off in March; new fronds will follow.
• Rot: In waterlogged soil, or if the crown is buried too deep, the plant rots. Plant in a well-drained spot and not too deep.

Through the year

• January: The green fronds decorate the winter garden.
• March: Cut off damaged fronds. Plant or divide.
• April: The new croziers unfurl. Add leaf mould.
• May: Plant. Water in dry spells.
• June: Growth. Water young plants.
• July: Water in dry spells.
• August: The spores ripen. Collect spores.
• September: Plant or divide.
• October: Plant.
• December: The glossy fronds stay green.

Did you know?

• The name scolopendrium comes from the Greek word for centipede: the lines of spore clusters on the underside look like a centipede’s legs.
• In towns it often appears by itself on old quay walls, in wells and on walls built with lime mortar.
• In the 19th century British fern enthusiasts collected countless unusual forms of hart’s-tongue fern, with crimped, crested or forked fronds.