Northern maidenhair fern

Northern maidenhair fern: how do you recognise it?

Habit

A loose, fan-shaped clump 40–50 cm tall and as wide, slowly spreading by a creeping rhizome.

Fronds

The stalk forks into two arms with side branches, so each frond forms a fan or horseshoe. The leaflets are small, fan-shaped to oblong and light green.

Stalks

Thin, glossy black to dark purple-brown: a striking contrast with the fresh green.

Spores

Under the folded-over edges of the leaflets, in summer.

Season

Deciduous: in autumn the fronds turn yellow-brown and die back; new growth appears in April–May.

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

Why grow it?

• One of the finest, most graceful ferns: airy foliage on black stalks.
• Fully hardy, despite its delicate look.
• Brings light and movement to a dark, shady corner.
• Slowly forms a broad clump without spreading aggressively.
• Lovely among hostas, epimediums and other shade plants, and in a large pot on a shady patio.
• Little work: just cut off the old fronds in spring.

Northern maidenhair fern: where does it grow best?

• Partial to full shade; morning sun is fine, but midday sun scorches the fine foliage.
• Humus-rich, light soil: sand or loam with plenty of leaf mould, acid to neutral.
• Evenly moist but well drained: it dislikes both waterlogging and drought.
• Sheltered from wind, which breaks the stalks and dries out the fronds.
• Plant 40–50 cm apart; in a group of three it becomes an airy cloud of foliage.

Light

Partial shade and shade

Soil type

Sand or loam

Acidity

Acid or neutral

Moisture

Normal

Size

0.5 m tall, 0.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Hosta: Large, broad leaves as a contrast with the fine fern foliage.
• Epimedium: A low ground cover for shade, with dainty flowers in April.
• Bleeding heart: Flowers in spring, while the fern is still low.
• Sweet woodruff: A low green ground cover with small white starry flowers in May.
• Japanese anemone: Flowers in late summer and autumn among the airy fronds.

Northern maidenhair fern: when and how to plant it?

Plant in March–May and September–October.

1. Plant from March to May or in September–October.
2. Dig a generous hole and mix in leaf mould or well-rotted compost.
3. Set the rhizome just below the surface, at the same depth as in the pot, without burying the crown.
4. Firm lightly and water thoroughly straight away.
5. Mulch with 3–5 cm of leaf mould to keep the soil cool and moist.

Care

Watering

Water generously in dry spells, especially in the first year and in pots. Drought leads to brown, shrivelled fronds.

Feeding

Little needed. A layer of compost or leaf mould in April is enough.

Mulching

Spread leaf mould around the base every spring; in autumn, simply leave fallen leaves where they lie.

Old fronds

Cut the dead fronds off in March, before the new ones appear.

In a pot

Use a wide pot with a drainage hole and humus-rich compost; keep it in the shade and water often in summer.

Tip: In autumn, leave fallen tree leaves around the fern: they keep the soil moist and rich in humus, just like the woodland it comes from.

Northern maidenhair fern: when to prune it?

Pruning months: March.

When: In March, before the new fronds emerge. Otherwise it needs no pruning.

How:

• Cut all dead fronds off just above the ground.
• Work carefully: the new curled fronds sit just below the surface and snap easily.
• In autumn, leave the dead fronds as a winter blanket and only clear them in March.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April, as growth starts: cut off a piece of rhizome with a few buds and roots, and replant it straight away.

Spores

In summer, collect ripe spores and sprinkle them on moist, sterile seed compost. Cover and keep in the light but out of the sun. It is slow, but it works.

Northern maidenhair fern: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy to about −30 °C: no protection needed in Belgium.
• The fronds die back in autumn; the rhizome overwinters safely underground.
• A layer of fallen leaves protects the rhizome and young fronds against late frost.
• In a pot: stand the pot against a sheltered wall and keep the compost slightly moist.

Diseases and pests

• Brown, dry fronds: Too much sun, wind or drought. Water, mulch and choose a shadier, more sheltered spot.
• Slugs: They can eat the young fronds in spring. Pick them off in the evening or lay down a board for them to hide under.
• Late frost: Frost in April–May can damage the young fronds. Cover with fleece; it usually regrows.
• Rot: In heavy, waterlogged soil the rhizome rots. Plant in light, free-draining soil rich in leaf mould.

Through the year

• March: Cut off dead fronds. Plant or divide.
• April: The new fronds unfurl. Spread leaf mould. Watch out for slugs and late frost.
• May: Plant. Water in dry spells.
• June: The fronds are fully grown. Water in dry spells.
• July: Water in dry spells, especially plants in pots.
• August: Collect ripe spores for sowing.
• September: Plant.
• October: Plant. The fronds turn yellow-brown.
• November: Leave dead fronds in place as a winter blanket.

Did you know?

• The name Adiantum comes from a Greek word meaning ‘unwettable’: water beads up and runs off the fronds.
• Pedatum means ‘foot-shaped’ and refers to the frond, which branches like a bird’s foot.
• The similar fern of western North America is now treated as a separate species, Adiantum aleuticum.