Marginal wood fern

Marginal wood fern: how do you recognise it?

Habit

Neat crown 40–60 cm tall and wide, with upright to arching fronds; evergreen.

Fronds

Leathery, blue-green, pinnate with lobed leaflets; stay green all year.

Spore clusters

Under the fronds are round clusters of spore cases along the edge of the leaflets, hence the species name.

Stalks

Covered with brown scales, especially on young fronds.

Reproduction

No flowers or seed: the fern reproduces by spores under the fronds.

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

Why grow it?

• Leathery, blue-green foliage that stays green all year, even in severe winters.
• Very hardy, to about −35 °C.
• Tolerates lime and fairly dry shade better than many other ferns.
• Does not spread and stays a neat crown.
• Little work: once a year cut off the damaged fronds.

Marginal wood fern: where does it grow best?

• Half shade to light shade; no strong midday sun.
• Well-drained, humus-rich soil: sand, loam or clay, acid to chalky.
• Tolerates fairly dry shade once established, but grows best in evenly moist soil.
• Allow 50–60 cm between plants. Also suits a rock garden or a north-facing wall.

Light

Partial shade and shade

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Dry or normal

Size

0.6 m tall, 0.6 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Cranesbill: A sturdy ground cover that also tolerates dry shade.
• Bergenia: Large, leathery leaves and pink flowers in spring.
• Hellebore: Flowers in winter next to the evergreen foliage.
• Barrenwort: A low ground cover with dainty flowers for dry shade.

Marginal wood 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 not frozen.
2. Dig a hole twice as wide as the root ball and mix in some leaf mould.
3. Set the fern at the same depth as in its pot, with the crown level with the soil surface. Do not bury the crown.
4. Plant 50–60 cm apart or one per pot of at least 30 cm across, with potting compost and a drainage hole.
5. Water thoroughly straight away and keep the soil moist during the first year.
6. Spread a layer of leaf mould around the plant and keep the crown free.

Care

Water

Regularly in the first year; after that only in long dry periods, more often in a pot.

Feeding

In spring a layer of leaf mould or organic fertiliser; no more is needed.

Mulching

A layer of leaf mould in spring keeps the soil cool and moist.

Tidying old fronds

In late winter cut off only the brown, damaged fronds.

Dividing

Rarely needed; you can divide a large crown in spring to rejuvenate it.

Tip: Choose a sheltered spot: it also does well on chalky soil or in fairly dry shade, and stays a neat crown that does not spread.

Marginal wood fern: when to prune it?

Pruning months: March.

When: From late February to March, before the new, rolled-up fronds appear.

How:

• Cut off only the brown, damaged or flattened fronds at the base.
• Leave healthy, green fronds; they stay attractive.
• Wear gloves: the scales on the stalks can irritate.
• Remove dead fronds from the heart of the crown.

Caution: Do not cut off new, rolled-up fronds: they are very fragile.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In spring carefully divide a large crown if it has side crowns; replant each rooted piece straight away and water.

Spores

In late summer collect ripe spores and scatter them on moist, sterile compost under glass or plastic. This takes months and the young plants grow slowly.

Marginal wood fern: how does it get through the winter?

Hardy to −35 °C.

• Very hardy, to about −35 °C: no protection is needed in Belgium.
• The foliage usually stays green; in severe frost or strong wind it may flatten or turn brown. Cut it back in spring.
• In a pot: place it against a wall, wrap the pot in hessian and keep the compost slightly moist.

Diseases and pests

• Brown leaf tips: Too dry or too much wind or sun. Water generously, mulch and choose a sheltered, shady spot.
• Slugs: Eat young, rolled-up fronds in spring. Collect them or lay a barrier of sharp sand.
• Crown rot: The crown goes soft and brown in wet soil. Ensure good drainage and do not plant the crown too deep.
• Winter damage: Flattened or brown foliage after frost or strong wind. Wait until spring and then cut off only the damaged foliage.

Through the year

• March: Cut off damaged foliage. Plant. Add compost.
• April: Plant. New fronds unroll.
• May: Plant. Keep an eye out for slugs.
• June: Water in dry spells.
• July: Water pots and in dry spells.
• August: Water. Collect spores if wanted.
• September: Plant.
• October: Plant. Leave leaves around the crown.
• December: Rest. The foliage stays green.

Did you know?

• The species name marginalis refers to the spore clusters that sit along the edge of the leaflets.
• It is also called leatherwood fern in English, after its sturdy, leathery foliage.
• Dryopteris species cross easily with one another, so natural hybrids exist.