Japanese painted fern

Japanese painted fern: how do you recognise it?

Habit

Loose, slowly spreading clump 30–40 cm tall and up to 50 cm across, with arching, fanning fronds.

Fronds

Triangular to lance-shaped, twice divided, 30–45 cm long; silvery grey with a green to purple sheen.

Veins

Midrib and stalk wine-red to purple, giving the frond a painted look.

Season

Deciduous: new fronds from April–May, dying back after the first frost.

Spores

Elongated spore clusters on the underside of the fronds; ferns do not flower.

Roots

Short, slowly creeping rhizome.

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

Why grow it?

• Silvery grey fronds with wine-red veins: colour in the shade without flowers.
• Attractive from May to the first frost, with the best colours on the young fronds.
• Fully hardy, to about −30 °C.
• A fine partner for hostas, coral bells and other shade plants.
• Grows slowly and stays compact: suits a small garden or a large pot.

Japanese painted fern: where does it grow best?

• Partial to light shade: this is where the colours are best. In full sun the fronds scorch; in deep shade they turn greener.
• Humus-rich soil: sand, loam or clay, acid to neutral, improved with leaf mould.
• Moist to fairly wet: it does not tolerate drying out in summer.
• Sheltered from drying winds and fierce midday sun.
• Plant 40–50 cm apart.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Acid or neutral

Moisture

Normal or wet

Size

0.4 m tall, 0.5 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Hosta: Blue-green or yellow-variegated leaves as a calm contrast to the silver.
• Coral bells: Purple and silver leaves that echo the colours of the fern.
• Barrenwort: An evergreen ground cover between the ferns.
• Wood anemone: Small white flowers in early spring, before the fern appears.
• Japanese forest grass: Fine, cascading grass for the same partial shade.

Japanese painted 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.
2. Dig a hole twice as wide as the pot and mix in leaf mould or well-rotted compost.
3. Set the plant at the same depth as in the pot, with the rhizome just at the surface; do not plant deeper.
4. Leave 40–50 cm between plants and firm the soil.
5. Water well straight away and keep the soil moist for the first few weeks.
6. Spread a layer of leaf mould or fine wood chips around the plant as a mulch.

Care

Water

Keep the soil moist, especially in the first year and in dry summers. Water at the base, in the morning.

Feeding

A thin layer of compost or leaf mould in spring; no more is needed.

Mulching

Leaf mould in spring and fallen leaves in autumn keep the soil cool and moist.

Marking

Put a stick next to the plant: it appears late and is easily forgotten or damaged when hoeing in spring.

In a pot

Humus-rich potting compost, a shady spot and regular watering; repot or divide every 2–3 years.

Tip: Give it a spot with morning sun or light shade: that is where the fronds colour best in silver and wine red. Keep the soil moist and humus-rich, because in full sun or dry soil the fronds scorch.

Japanese painted fern: when to prune it?

Pruning months: March.

When: In March, before the new fronds appear.

How:

• Leave the dead fronds standing over winter: they protect the rhizome.
• In March, cut all the old brown fronds off just above the ground.
• In summer, remove any scorched or damaged fronds if needed; new ones will follow.

Caution: Watch out for the young fiddleheads: they only appear in April–May and snap easily.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April, lift the clump and cut it into pieces with a sharp spade or knife, each with a piece of rhizome and buds. Replant straight away and water well.

Spores

Collect ripe spores in late summer and sow them under glass on sterile, moist seed compost. The young plants may differ in colour from the parent.

Japanese painted fern: how does it get through the winter?

Hardy to −30 °C.

• Fully hardy, to about −30 °C: no protection needed in the garden.
• The fronds die back in autumn; leave them as natural protection and only cut them off in March.
• In a pot: stand it sheltered against a wall or in a cold shed, so the root ball does not freeze solid; keep the compost slightly moist.
• The new fronds appear late; a late frost can damage them, but the plant will regrow.

Diseases and pests

• Scorched fronds: Brown, crisp frond edges: too much sun or too dry. Water, mulch and if necessary move the plant to more shade.
• Late frost: Blackened young fiddleheads in May. Cover with fleece when frost is forecast; the plant usually regrows.
• Slugs: Eat the young fronds. Pick them off in the evening, or lay down a board as a hiding place and clear it in the morning.
• Vine weevil: Mainly in pots: the grubs eat the roots and the plant collapses. Use nematodes against the grubs in spring or late summer.

Through the year

• March: Cut away old fronds. Spread compost or leaf mould.
• April: Plant or divide. Mark the spot, as it appears late.
• May: New fronds unfurl. Watch for slugs and late frost.
• June: Best colour on the young fronds. Water in dry spells.
• July: Water in dry spells.
• August: Water in dry spells. Collect ripe spores.
• September: Plant or divide.
• October: Plant. Leave fallen leaves around the plant.
• November: The fronds die back; leave them as protection.

Did you know?

• In 2004 it was named perennial plant of the year in the United States.
• Plants raised from spores are never quite identical: each can have a slightly different shade of silver and red.
• Despite its colours it has no flowers: like all ferns, it reproduces by spores.