Sword fern
Polystichum munitum · Dryopteridaceae
📷 Jami Dwyer · CC BY-SA 2.0
The gardener's calendar
Ideal time to plant sword fern: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Evergreen, dark green
- Plant type
- Fern
- Adult size
- Up to 100 cm in height
- Growth
- Slow to moderate
- Hardiness
- Hardy down to -15°C
- Origin
- West coast of North America (Pacific)
- Soil type
- Rich, well-drained, slightly acidic
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Water regularly during growth (spring-summer), very sparingly but never let it fully dry out in winter. Evergreen foliage: clean it annually in October (pass damp hand over leaves, remove debris).
The common mistake
Thinking that in shade it thrives without water: it suffers from dry air.
The pro's trick
Propagate via bulbils (small basal plantlets): detach them in April, replant in moist potting soil.
Care
Light exposure
Sword fern prefers shaded to semi-shaded areas. It dreads direct sun which can burn its delicate foliage. Install it under tree cover or in a shaded, protected corner of your garden.
Watering
Keep the soil moist but well-drained, without waterlogging. Water regularly during the growing season (spring-summer), reducing in autumn-winter. Make sure the substrate never dries out completely.
Soil
Prepare rich, organic soil that is light and well-drained. Adding peat or compost at planting improves structure. The fern appreciates slightly acidic to neutral soil.
Fertilising
An annual application of balanced fertiliser in spring is sufficient. You can also add compost or organic mulch which nourishes the soil gradually while retaining moisture.
Pruning
Remove only dead or damaged fronds by cutting at the base with clean tools. No drastic pruning needed: sword fern naturally adopts a beautiful, compact shape.
Diseases and pests
Generally hardy, it can be troubled by scale insects or spider mites in very dry indoor conditions. Increase humidity and ventilation to prevent problems. Root rot is rare if drainage is correct.
Did you know?
The sword fern, named for its narrow, pointed fronds, was used by indigenous peoples of North America to line their dwellings. Its rhizomes spread slowly underground, creating true colonies over the years, which allows it to regenerate damaged foliage quickly.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- Scaly Male FernDryopteris affinis
- Soft shield fernPolystichum setiferum
- Autumn fernDryopteris erythrosora
- Japanese holly fernCyrtomium falcatum
- Asian netvein hollyfernCyrtomium fortunei
- Korean rock fernPolystichum luctuosum
Tips generated and checked by Viridia — adapt them to your local climate.