Western sword fern
Polystichum munitum · Polypodiaceae Popular
Long, dark, leathery fronds like swords form a large evergreen clump. It is the signature fern of Pacific Northwest forests, where it carpets the ground under conifers.
- Size
- 3½ ft tall, 3½ ft wide
- Zones
- 5 to 9
- Light
- Part shade to shade
- Flowers
- Grown for its leaves
- Pets
- No toxicity recorded
- Job in a bed
- Specimen
A bed built around western sword fern
The planner designed this bed around western sword fern when this page was made: a 12 × 6 ft (3.7 × 1.8 m) English border in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why western sword fern stands where it does.
The plants
- 1 Western sword fern × 1, dark green leaves
- 2 Moor grass 'Greenlee' × 8, tan
- 3 Leadwort × 8, blue
- 4 Turtlehead 'Hot Lips' × 3, pink
- 5 Gray's sedge × 3, green
- 6 Lowbush blueberry × 5, white
- 7 Early crocus × 12, lavender
- 8 Yellow trout lily × 7, yellow
Why this plant
- The only plant grown for its leaves. Leaf lasts all season, where a flower lasts a few weeks.
Why here
- Anchors a back corner. At 3½ ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to Gray's sedge (2½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- Here for its leaves, all year. They cover the 10 weeks between early March and late November when nothing on the plan is in flower.
- The only leaves in winter. From November to March it is what there is to look at.
Planned as an English border: 4 of the 6 groups (67%) are drifts, longer along the bed than they are deep. Western sword fern and turtlehead 'Hot Lips' anchor the back corners of the bed: the tallest plants on the plan stand there. The most in flower at one time is 4 kinds, from mid August.
The planner's own design check: 13 Excellent, 4 Good. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where western sword fern goes in a border
At 3½ ft it belongs at the back of a bed. In the planner's ten height classes it is moderately tall (3 to 4 ft).
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
In its home region nothing is tougher or more fitting under tall trees. It is less happy in the hot, humid summers of the East.
- Large evergreen ferns
- Dry shade under conifers in the West
- Massing on slopes
What to plant with western sword fern
Plants recorded as good partners for it, and what each pairing does:
- Bleeding heart: adds the flowers, early May to early June.
- Hosta: bold leaves against its medium ones; low enough (18 in) to stand in front of it.
- Deer fern: low enough (16 in) to stand in front of it.
Questions about western sword fern
Does western sword fern need sun or shade?
Western sword fern grows in part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light).
It wants ordinary well-drained soil, of average fertility, and a good soak in dry spells.
What zones does western sword fern grow in?
USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
How far apart should western sword fern be planted?
3 ft (90 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 3½ ft (110 cm), so a group knits into one patch.
It grows 3½ ft (110 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many western sword fern plants do I need?
At 3 ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 4 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is western sword fern poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Do deer eat western sword fern?
They may. NC State does not list it as resistant to deer or rabbits. Where they visit, protect it, or plant it among ones they avoid.
What does western sword fern look like in winter?
Western sword fern keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
Is western sword fern good for bees and butterflies?
Western sword fern is visited by songbirds.
It is native to the United States and Canada.
More Polystichum
- Braun's holly fern Polystichum braunii
- Christmas fern Polystichum acrostichoides
- Korean rock fern Polystichum tsus-simense
- Makino's holly fern Polystichum makinoi
- Soft shield fern Polystichum setiferum
- Tassel fern Polystichum polyblepharum
In these guides
Every fact on record
- Type
- Fern
- Size
- 3½ ft (110 cm) tall, 3½ ft (110 cm) wide
- Plant
- 3 ft (90 cm) apart
- Height class
- Moderately tall (3 to 4 ft)
- Place in the bed
- Back
- Flowers
- None: grown for its foliage
- Leaves
- Medium texture, evergreen; dark green
- Shape
- Vase-shaped, clumping
- Hardy in
- USDA zones 5 to 9
- Light
- Part shade, shade
- Soil
- Average, well-drained
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Polypodiaceae
- Comes from
- Western North America, Alaska, British Columbia to Mexico
- Attracts
- Songbirds
Checked against NC State Extension. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.