Western sword fern Polystichum munitum
Western sword fern (Polystichum munitum) is an evergreen perennial groundcover in the Dryopteridaceae family, native to Pacific coast of western North America (Alaska to California). It grows 60 cm–1.2 m (24 in–3.9 ft) tall and 80 cm–1.2 m (31 in–3.9 ft) wide, wants part sun to part shade and moderate water, and is hardy to about -23 °C (-9 °F). Space plants about 90 cm (35 in) apart.
Plan Western sword fern in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Western sword fern at a glance
| Type | Perennial groundcover, evergreen |
|---|---|
| Family | Dryopteridaceae |
| Mature height | 60 cm–1.2 m (24 in–3.9 ft) |
| Mature spread | 80 cm–1.2 m (31 in–3.9 ft) |
| Spacing | 90 cm (35 in) centre to centre |
| Sun | Part sun to part shade, at least 3 h of direct sun a day |
| Water | Moderate; drought tolerance moderate, waterlogging tolerance low |
| Soil pH | 5.5–7 |
| Cold hardiness | About -23 °C (-9 °F) once established (roughly USDA zone 6) |
| Heat stress | Likely above about 30 °C (86 °F) |
| Wind tolerance | Low |
| Pollinator value | None |
| Edible | Not grown as food |
| Native to | Pacific coast of western North America (Alaska to California) |
| Common in gardens of | 🇺🇸 United States |
Is Western sword fern toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
No toxicity reported in ASPCA or standard poison references.
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 Western sword fern
No well-documented helpful pairing. Group it with plants that like part sun to part shade and moderate water.
See Western sword fern in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- UC Botanical Garden, Berkeley (50 plants)
- The Butchart Gardens (38 plants)
Questions about Western sword fern
- How far apart should I plant Western sword fern?
- About 90 cm (35 in) apart, centre to centre. A mature plant spreads 80 cm–1.2 m (31 in–3.9 ft).
- Does Western sword fern need full sun?
- Part sun to part shade: at least 3 hours of direct sun a day.
- How much water does Western sword fern need?
- Moderate water. Drought tolerance is moderate and waterlogging tolerance low.
- How cold-hardy is Western sword fern?
- It tolerates about -23 °C (-9 °F) once established, roughly USDA zone 6.
- Is Western sword fern poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. No toxicity reported in ASPCA or standard poison references.
- What grows well with Western sword fern?
- There is no well-documented companion pairing for Western sword fern. Group it with plants that like the same sun (part sun to part 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
- USDA PLANTS Database, USDA NRCS
Notes and assumptions
- Ferns do not flower; flowering values are placeholders.
- Old fronds accumulate and are flammable in dry summers; remove dead fronds near buildings.
- Tolerates dry shade once established but looks best with summer 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.
Related plants
- Male fern Dryopteris filix-mas
- Christmas fern Polystichum acrostichoides
- Creeping thyme Thymus serpyllum
- Hosta Hosta spp.
- Lamb's ear Stachys byzantina
- Stonecrop (sedum) Hylotelephium spectabile
- Sweet woodruff Galium odoratum
- Lady's mantle Alchemilla mollis