Western Sword Fern care — light, water, toxicity and hardiness
Western Sword Fern (Polystichum munitum) wants partial shade and a drink about every 7 days once established. It is hardy in USDA zones 5 to 9. It is safe to have around pets.
| scientific name | Polystichum munitum |
|---|---|
| family | Dryopteridaceae |
| category | fern |
| plant type | perennial |
| light | partial shade |
| water cadence days | 7 |
| mature height cm | 120 |
| min zone | 5 |
| max zone | 9 |
| frost tolerant | true |
| toxic to pets | false |
| toxic to humans | false |
| edible | false |
How often should I water Western Sword Fern?
Pacific Northwest native; evergreen; drought-tolerant in shade.
Who eats it
Palatable to people: no.
What it needs
Its shade tolerance is low. Its moisture use is high. Its drought tolerance is low. It wants at least about 16 inches of rain a year. Above roughly 55 inches of annual rain it struggles. It tolerates soil down to pH 5.8. It tolerates soil up to pH 7.5. Its fertility requirement is medium. Adapted to coarse, sandy soils: no. Adapted to medium, loamy soils: yes. Adapted to fine, clay soils: no. Its tolerance of waterlogging is low. It needs at least 135 frost-free days. Its tolerance of chalky soil is medium. Its fire tolerance is medium. Fire resistant: no. It has been recorded down to -33°F. It suppresses neighbours chemically: no.
How it grows
It grows as a rhizomatous form. Its growth rate is moderate. Its lifespan is long. It puts on most of its growth in spring, summer, fall. It spreads vegetatively at a moderate rate. It resprouts after damage: no. Coppices: no. At maturity it reaches about 3.5 feet. Its roots go down at least 14 inches. Its shape is semi-erect. It holds its leaves through winter: no.
What it looks like
The flowers are brown. Conspicuous in flower: yes. The foliage is dark green. The foliage texture is medium. In summer the canopy is dense in porosity. In winter it is moderate in porosity. Fall colour: yes. The fruit persists on the plant: no. The fruit is conspicuous: no.
Growing more of it
Propagated by seed: no. Propagated by cuttings: no. Propagated by container: yes. Propagated by bare root: no. Propagated by bulb: no. Propagated by corm: no. Propagated by tubers: no. Cold stratification required: no. Commercial availability: contracting only.
Source: Drafted from US Cooperative Extension horticulture guidance; pending HUMAN-05 review (issue 280) · ASPCA Toxic and Non-Toxic Plant List · 2026-09-02