Boston swordfern
Nephrolepis exaltata · Nephrolepidaceae
📷 Wikimedia Commons · CC BY-SA 3.0
The gardener's calendar
Ideal time to plant boston swordfern: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Foliage
- Evergreen, light green
- Plant type
- Tropical fern
- Adult size
- 60 cm tall, spreading and trailing habit
- Growth
- Moderate to rapid under optimal conditions
- Hardiness
- Not hardy, indoor plant (tropical climate)
- Origin
- Tropical and subtropical America
- Light
- Indirect light, partial shade
- Water needs
- High, constantly moist soil
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability medium.
Expert tips
The key tip
Nephrolepis exaltata loves constant atmospheric humidity but not waterlogged soil; increase ambient humidity and keep the soil preferably slightly moist. Repot each spring to refresh the substrate, which depletes quickly.
The common mistake
Letting the air dry out or the soil dry between waterings: frond tips turn brown, growth stalls, and spider mites move in.
The pro's trick
Place the pot on a tray filled with moist clay pellets without the pot sitting in water; humidity rises and you won't worsen root rot.
Care
Regular watering
Boston ferns love constantly moist substrate but never waterlogged. Water as soon as the soil begins to dry slightly on the surface. Rainwater or distilled water is preferable to tap water which is too chalky. In winter, reduce watering frequency slightly.
Light and exposure
Place your fern in indirect light or partial shade: near a window without intense direct sun, ideally facing north or east. Insufficient light slows growth and weakens the foliage. Avoid direct rays which scorch the delicate fronds.
Pruning and cleaning
Remove yellowed, dried or damaged fronds as they appear by cutting them at the base. Clean leaves regularly with a soft damp cloth to remove dust and encourage photosynthesis. No drastic pruning needed: the fern regenerates naturally.
Moderate fertilizing
Apply a very diluted balanced fertilizer once a month during the growing season (spring and summer). Reduce to once every two months in autumn and stop fertilizing in winter. Too much fertilizer burns delicate roots.
Substrate and drainage
Use light, airy potting mix, a blend of peat, sphagnum moss and perlite. Good drainage is essential to prevent root suffocation. Repot every two years in spring into a slightly larger pot.
Problem prevention
Watch for spider mites and mealybugs, especially in dry air. Increase humidity by misting regularly or placing the plant on a tray of damp pebbles. Root rot can occur if soil stays too waterlogged: improve drainage and reduce watering.
Did you know?
Boston ferns became famous in the early 20th century as Victorian hothouse plants before conquering modern interiors. A natural mutation of the bird's nest fern discovered in Florida, it was intensively cultivated as an elegant houseplant, a symbol of greenery for urban homes. Its worldwide success makes it one of the most popular ferns in the horticultural trade.
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
- Narrow swordfernNephrolepis cordifolia
- Giant swordfernNephrolepis biserrata
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- SageSalvia officinalis
Tips generated and checked by Viridia — adapt them to your local climate.