Aleutian maidenhair fern

Aleutian maidenhair fern: how do you recognise it?

Habit

Upright to slightly arching clump about 50 cm tall and wide; it spreads slowly by short rhizomes.

Fronds

Fan-shaped: the stalk divides at the top into a half-circle of fingers bearing small, oblong, fresh green leaflets.

Stems

Thin, shiny and black to dark purplish brown.

Spores

Ferns do not flower; the spores sit under the folded-over edges of the leaflets.

Roots

Short, creeping rhizomes just below the surface.

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

Why grow it?

• One of the most graceful ferns for the shade garden, with airy, almost lace-like foliage.
• The shiny black stems make a lovely contrast with the fresh green leaves.
• Fully hardy and sturdier than many other maidenhair ferns.
• Ideal for a moist, shady corner, under trees or on the north side of the house.
• Little work: just cut away the old fronds once a year.

Aleutian maidenhair fern: where does it grow best?

• Part shade or shade; no fierce midday sun, which scorches the leaves.
• Loose soil rich in humus: sand or loam with plenty of leaf mould, acid to chalky.
• Evenly moist: do not let it dry out, but no standing water either.
• Sheltered from wind; allow 40–50 cm per plant.

Light

Partial shade and shade

Soil type

Sand or loam

Acidity

Not fussy

Moisture

Normal

Size

0.5 m tall, 0.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Hosta: Large, broad leaves beside the fine fern foliage, in the same shade.
• Barrenwort: A low ground cover with dainty spring flowers.
• Bleeding heart: Pink or white heart-shaped flowers in spring, as the fern unfurls.
• Japanese forest grass: Arching green or golden grass that contrasts nicely with the fan-shaped fronds.
• Lungwort: Spotted leaves and early flowers in the same moist shade.

Aleutian maidenhair fern: when and how to plant it?

Plant in March–May and September–October.

1. Plant in March–May or in September–October, when the soil is moist but not wet.
2. Dig a generous hole and mix in plenty of leaf mould or well-rotted compost.
3. Set the plant at the same depth as it was in the pot: the rhizome belongs just below the surface, no deeper.
4. Keep 40–50 cm between it and other plants.
5. Water in well straight away and keep the soil moist for the first few months.
6. Spread a layer of leaf mould or fine wood chips around the plant.

Care

Watering

Water regularly in dry weather, especially in the first year: the fine leaflets dry out quickly.

Feeding

A layer of leaf mould in spring is enough; ferns need little fertiliser.

Mulching

A layer of leaf mould every spring or autumn keeps the soil cool, moist and rich in humus.

Old fronds

Leave them over winter and cut them away in March, before the new fronds unfurl.

Shelter

A spot out of the wind stops the fine fronds snapping and drying out.

Tip: Plant it where you can see the shiny black stems, for instance at the front of a shade border or beside a path. Keep the soil moist with a layer of leaf mould and choose a spot out of the wind.

Aleutian maidenhair fern: when to prune it?

Pruning months: March.

When: In March, before the new fronds unfurl. Otherwise no pruning is needed.

How:

• Cut the old, dead fronds off at the base.
• Watch out for the young, coiled fronds already coming through the soil: do not cut them off as well.
• Broken or dried-out fronds can simply be cut off at the base in summer.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April, just before new growth: lift the clump and cut the rhizome into pieces, each with a few growing points and roots. Replant them straight away at the same depth.

Spores

In summer, when the spore clusters under the leaflet edges are brown: lay a frond on paper, let the spores drop and sow them on moist, sterile compost under glass or plastic. It takes patience: it is months before you have a small plant.

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

Hardy to −30 °C.

• Fully hardy, to about −30 °C: in Belgium no protection is needed.
• The fronds die back in autumn; leave them as natural protection for the rhizome.
• A layer of leaves or leaf mould in autumn keeps the soil rich in humus and protects against frost.
• In a pot: stand it against a wall in winter, out of the wind, and keep the compost slightly moist.

Diseases and pests

• Dried-out fronds: Brown, crispy leaflets caused by drought, wind or too much sun. Water, mulch and choose a sheltered, shady spot.
• Late frost: Frozen young fronds in April–May. On a frosty night, cover the plant with fleece; usually new fronds follow.
• Slugs: They sometimes eat the young, emerging fronds. Check in the evening in spring and remove them.
• Yellow fronds: Often on wet, poorly drained soil. Mix leaf mould and some coarse sand into the soil or choose a slightly higher spot.

Through the year

• March: Cut away old fronds. Plant. Divide.
• April: The new fronds unfurl. Plant. Mulch with leaf mould.
• May: Plant. Water in dry spells. Watch out for slugs.
• June: Water in dry spells.
• July: Collect spores when the clusters are brown. Water in dry spells.
• August: Water in dry spells.
• September: Plant.
• October: Plant. Spread a layer of leaves around the plant.
• November: Leave dead fronds in place as protection.

Did you know?

• Adiantum comes from the Greek ‘adiantos’, unwetted: water droplets roll off the fronds without making them wet.
• Botanists long regarded this fern as a form of Adiantum pedatum; only in the late 20th century was it recognised as a separate species.
• In the wild it grows, among other places, on serpentine, a type of rock on which very few plants can grow.