Japanese painted fern Athyrium niponicum
Japanese painted fern (Athyrium niponicum) is a deciduous perennial groundcover in the Athyriaceae family, native to Japan, Korea and eastern China. It grows 30–50 cm (12–20 in) tall and 40–60 cm (16–24 in) wide, wants shade and moderate water, and is hardy to about -34 °C (-29 °F). Space plants about 40 cm (16 in) apart.
Plan Japanese painted fern in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Japanese painted fern at a glance
| Type | Perennial groundcover, deciduous |
|---|---|
| Family | Athyriaceae |
| Mature height | 30–50 cm (12–20 in) |
| Mature spread | 40–60 cm (16–24 in) |
| Spacing | 40 cm (16 in) centre to centre |
| Sun | Shade, at least 2 h of direct sun a day |
| Water | Moderate; drought tolerance none, waterlogging tolerance low |
| Soil pH | 5.5–7 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 28 °C (82 °F) |
| Wind tolerance | None |
| Pollinator value | None |
| Edible | Not grown as food |
| Native to | Japan, Korea and eastern China |
| Common in gardens of | 🇯🇵 Japan, 🇺🇸 United States |
Is Japanese painted fern toxic?
- People: not well documented
- Cats: not well documented
- Dogs: not well documented
No toxicity clearly documented in ASPCA or standard poison references; treat as untested.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Japanese painted fern
No well-documented helpful pairing. Group it with plants that like shade and moderate water.
See Japanese painted fern in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- The Butchart Gardens (10 plants)
- Monet’s gardens at Giverny (16 plants)
- Riverside botanical garden (8 plants)
Questions about Japanese painted fern
- How far apart should I plant Japanese painted fern?
- About 40 cm (16 in) apart, centre to centre. A mature plant spreads 40–60 cm (16–24 in).
- Does Japanese painted fern need full sun?
- Shade: at least 2 hours of direct sun a day.
- How much water does Japanese painted fern need?
- Moderate water. Drought tolerance is none and waterlogging tolerance low.
- How cold-hardy is Japanese painted fern?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- Is Japanese painted fern poisonous to cats and dogs?
- For cats it is not well documented; for dogs not well documented; for people not well documented. No toxicity clearly documented in ASPCA or standard poison references; treat as untested.
- What grows well with Japanese painted fern?
- There is no well-documented companion pairing for Japanese painted fern. Group it with plants that like the same sun (shade) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- RHS Plant Finder, Royal Horticultural Society
- Extension Gardener Plant Toolbox, NC State Extension
Notes and assumptions
- Ferns do not flower; flowering values are placeholders.
- Silver and burgundy fronds (var. pictum) colour best in light shade with steady moisture.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
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