Siebold's wood fern

Sun

Partial to full shade; protect from hot afternoon sun.

Water

Keep evenly moist while establishing. Established plants tolerate brief dry spells, but prolonged drought damages the foliage.

Soil

Humus-rich, moist but well-drained soil; slightly acidic to neutral is ideal. Avoid waterlogged ground.

Height

1.5-2.5 ft (0.45-0.75 m)

Spread

2-3 ft (0.6-0.9 m)

Foliage

Evergreen. Arching, leathery, dull blue-green fronds with a few pairs of broad, tapering leaflets and a prominent terminal leaflet. Spore-bearing patches develop beneath mature fronds.

Growth

Slow

Care needed

Low

• Deer resistant
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.2 ft (0.36 m)

3. After 2 years

   1.4 ft (0.42 m)

4. After 3 years

   1.6 ft (0.49 m)

5. After 5 years

   2 ft (0.6 m)

   full size

About 5 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Mildly toxic: may upset a stomach

Growth rate

Slow

• Water deeply when the upper soil begins to dry, especially during the first growing season.
• Apply leaf mould or compost as a mulch in spring, keeping it clear of the crown.
• Shelter from drying winds and strong afternoon sun.
• Avoid heavy feeding; a light annual compost dressing is usually sufficient.
• Leave established clumps undisturbed unless division is needed.

Pruning. In late winter or early spring, cut damaged or dead fronds back to the base before new growth unfolds. Retain healthy evergreen fronds and avoid cutting emerging shoots.

Late winter

Check for frost-damaged fronds and remove them before new shoots emerge.

Spring

Plant or divide established clumps, keeping the crown at soil level.

Mid-spring

Mulch with leaf mould or compost without covering the crown.

Summer

Water during dry spells and check that nearby tree roots are not leaving the soil dry.

Autumn

Remove heavy accumulations of fallen leaves from the crown, but retain a light mulch around the plant.

Winter

Leave sound fronds in place and check that the planting area drains freely.

• Plant beneath deciduous trees where its broad leaflets contrast with finer woodland foliage.
• Combine with hostas and barrenworts in a shaded border for contrasting leaf shapes.
• Use beside a shaded path or courtyard wall where its distinctive fronds can be seen close up.
• Grow in a large, well-drained container in a sheltered shady courtyard; protect the roots from severe winter freezing.

Garden styles it suits: Woodland, Japanese, Moss and fern garden, Green on green, Modern courtyard and Secret garden.

Plant it with: Hosta, Barrenwort, Japanese forest grass, Hellebore, Lungwort and Japanese painted fern.

Wildlife: The clump offers shelter for small invertebrates. It has no flowers or nectar and is not a significant food plant for pollinators.

• Brown, scorched fronds in strong sun or drying wind: provide more shade and shelter, and maintain soil moisture.
• Crown or root rot in saturated soil: improve drainage and keep mulch away from the crown.
• Slugs and snails damaging emerging fronds: inspect at dusk, remove them by hand, or use locally approved iron-phosphate bait as directed.
• Winter-browned foliage: shelter from cold winds and remove damaged fronds before spring growth; avoid exposed sites near the cold limit of its range.

Reliable species-specific toxicity information for people, cats, dogs and horses is limited. Treat the fronds and rhizomes as potentially harmful if eaten because some related wood ferns contain toxic compounds; the severity of poisoning from this species is not well established.

• Japanese holly fern (Cyrtomium falcatum)

  Usually has more numerous, glossy dark-green, often sickle-shaped leaflets. Siebold's wood fern has fewer, broader, dull blue-green leaflets.

• Shaggy shield fern (Dryopteris cycadina)

  Has many more narrow, toothed leaflets and conspicuously dark-scaled stalks, rather than the few broad leaflets of Siebold's wood fern.

The species name sieboldii and the common name honour Philipp Franz von Siebold, a physician and plant collector who studied Japanese plants.

Propagation. Divide a mature clump in spring, retaining healthy roots and growing points on each section. It can also be raised from spores, but this is slow and requires consistently moist, clean conditions.

Accepted botanical name

Dryopteris sieboldii

Native range

China South-Central, China Southeast and Japan.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.