Houseplant
Boston Fern
Nephrolepis exaltata 'Bostoniensis' · Nephrolepidaceae (Lomariopsidaceae)
Also called: Sword Fern, Ladder Fern
Boston Fern (Nephrolepis exaltata 'Bostoniensis') is a high-water houseplant well suited to Tucson and the low desert. It's a moderate-growing houseplant. Expect n/a (non-flowering) blooms None.
Boston Fern at a glance
- Water use
- High (established)
- Sun
- Bright indirect light indoors; no direct desert sun. An east-facing window or filtered light is ideal.
- Mature size
- Indoors typically 1-3 ft tall and 2-3 ft wide in a hanging basket.
- Growth rate
- Moderate
- Bloom
- N/A (non-flowering), None; ferns are non-flowering and reproduce by spores.
- Cold hardiness
- Frost-tender; keep above 50-55 F indoors. Not winter-hardy outdoors in Tucson.
- Soil
- Rich, moisture-retentive but well-draining peat/coir-based mix.
- Native range
- Humid tropical regions of the Americas; cultivar selected from Nephrolepis exaltata, native to Florida, the West Indies, and Central/South America
- Best used as
- Indoor hanging basket, Humid-room foliage (bathrooms), Shaded covered-patio plant in mild months, Air-purifying houseplant
- Wildlife
- None relevant indoors.
- Toxicity
- Non-toxic to cats, dogs, and humans (ASPCA lists Boston/sword ferns as safe); pet- and child-safe.
How to grow Boston Fern in Tucson & the low desert
Watering
Keep the soil consistently and evenly moist (never soggy, never bone-dry). In Tucson's extremely low indoor humidity this fern dries out fast, so check every few days; it may need water 2-3 times a week in summer. Browning frond tips signal too-dry air or salty water.
Fertilizer & nutrients
Feed lightly monthly spring through summer with a balanced, dilute (half-strength) liquid fertilizer; ferns are sensitive to fertilizer salts, so under-feed rather than over-feed and flush pots to clear salt from Tucson's hard water.
Pruning & care
Trim off dead or yellowed fronds at the base to keep the plant tidy; can be cut back hard if it gets ragged and will regrow.
Notes
Among the most humidity-demanding houseplants for Tucson; the low desert's dry air is its biggest challenge. Use a pebble tray, group with other plants, or place in a bathroom, and avoid hot dry drafts from heating/AC vents. Can summer outdoors only in deep, protected shade and will still need frequent watering and misting.
Sources: University of Arizona Cooperative Extension; ASPCA Toxic and Non-Toxic Plant List; Missouri Botanical Garden Plant Finder