# Boston fern (Nephrolepis exaltata)

Canonical: https://plantguide.ae/plants/boston-fern · Updated: 2026-10-07
Source: Plant Guide (https://plantguide.ae/plants/boston-fern)

Boston fern · also called Sword fern, Fluffy ruffles  
indoor · exotic · family Nephrolepidaceae · grows 0.4–0.9 m tall, 0.5–1 m wide · moderate growth  
part shade · high water need  
Ratings for Dubai (1–5, 5 is best): heat 1 · salt 1 · drought 1 · shade 3 · ease of care 2  
Sow or plant: Feb–Apr, Oct–Nov  
Uses: indoor, container

A lush, arching fern that is non-toxic to cats and dogs (ASPCA) but thirsty and humidity-hungry. It suits a bright bathroom or kitchen window far better than an air-conditioned living room.

## About

Meet Boston fern, the plant that makes a shelf look like a woodland. Its long, arching fronds are cut into hundreds of small leaflets, and a healthy plant forms a soft green fountain that spills over the edge of a pot, basket or plinth. Few houseplants fill space so generously for so little money.

It is also honest about what it needs. NC State Extension says the soil should never dry out and that the fern wants high humidity, and suggests placing it near kitchens and bathrooms. The RHS asks for bright filtered light, moderate to high humidity and good ventilation, and says it dislikes dry compost and cold draughts. An air-conditioned Dubai living room offers the reverse, so Boston fern is a plant for the right room, not for any room.

Give it that room, a bright bathroom or kitchen with a window, and it rewards you with a full, glossy plant. Put it by a vent and the fronds crisp from the tips.

Boston fern is the cultivar group of sword fern known as Nephrolepis exaltata 'Bostoniensis', an evergreen fern that spreads by runners. The RHS gives 0.5 to 1 metre tall and wide, reached in two to five years; NC State gives 2 to 3 feet. In a flat, a 20 to 30 cm plant is typical, and it grows into a basket-sized specimen over time.

Light should be bright but filtered. NC State says bright, indirect light, and that it tolerates deep shade of less than two hours of direct sun; the RHS says it dislikes bright, direct sunlight. In Dubai that means a bathroom or kitchen window, a metre or two back from tinted or low-E glass, with no hot afternoon sun.

Humidity and water are the whole game. NC State says it needs high humidity and moist soil that should never dry out, and that scale insects and spider mites thrive in dry air. The RHS says to water moderately in the growing season with soft water and sparingly in winter, and that fronds can rot if they stay wet. In practice that means a windowed bathroom or a humidifier in the room; only a humidifier changes room humidity, and misting does not (UNL Extension). Use filtered water where you can.

The ASPCA lists Boston fern as non-toxic to dogs and cats, which makes it one of the easier ferns for a pet household, though eating any plant can still upset a stomach.

## Indoors in Dubai

- **Light:** grows well in medium–bright indirect light. Bright, indirect light; it tolerates shade but not hot glass. A bathroom or kitchen window, a metre or two back from tinted or low-E glass and out of afternoon sun, suits it.
- **Dry air and air conditioning:** tolerance 1 out of 5 (1 = needs humidity help, 5 = indifferent). Dry AC air crisps the fronds fast. Keep it out of the vent's airflow, group it with other plants and run a humidifier nearby, since misting does not raise room humidity. Never let the soil dry out.
- **Pets:** pet-safe: not toxic to cats or dogs on the ASPCA list.
- **Size:** medium size.
- **Rooms:** bathroom, kitchen, living room.
- **Finding it in Dubai:** common: most garden centres and supermarkets stock it.
- **Outdoors:** never: keep it indoors all year.

## Through the year

Boston fern stays green all year, so its calendar is about water, humidity and pests rather than looks. April to September is its growing season: feed at half strength once a month (RHS) and check the undersides of the fronds for scale and spider mites, which thrive in dry air (NC State). Air conditioning runs continuously in many Dubai homes from about May to October (Murtagh et al., 2022), which is when fronds crisp fastest, so keep it away from vents and add humidity. From December to February growth slows; water more sparingly (RHS), but never let the soil dry out completely (NC State). October to November and February to April are the months to buy and pot up.

| When | What | Note |
| --- | --- | --- |
| Feb–Apr, Oct–Nov | Plant: Buy and pot up | Cooler months, so the plant is not carried home in summer heat. |
| Apr–Sep | Feed: Half-strength monthly feed | The RHS says a half-strength balanced liquid fertiliser once a month during the growing season. |
| Mar–Oct | Pest watch: Check for scale and spider mites | NC State says both thrive in dry air. |
| Jun–Sep | Heat stress: Hot glass and dry AC air | Fronds crisp fastest when AC runs all day; keep clear of vents and hot windows. |
| Dec–Feb | Dormant: Growth slows | Water more sparingly, but never let the compost dry out completely. |

## Care in Dubai

- **Watering in summer:** Never let the soil dry out (NC State). Check every few days and water as soon as the surface begins to dry, using filtered water if you can. In an air-conditioned room the pot can dry faster than you expect, and the fronds crisp quickly if it does.
- **Watering in winter:** Water more sparingly (RHS), but do not let the compost dry out completely, and never leave the fronds wet: they can rot.
- **Soil:** A peat-free multipurpose compost that stays moist but drains well (RHS), in a pot with drainage holes.
- **Feeding:** A half-strength balanced liquid fertiliser once a month during the growing season (RHS), roughly April to September in Dubai.
- **Pruning:** Cut dead fronds off at the base (RHS).
- **Planting:** Repot in spring when roots fill the pot. Propagate by separating rooted runners in late winter or early spring (RHS). Dark brown or black dots under the fronds are spores, not pests (NC State).
- **Pests and problems:** Scale insects; Spider mites
- **Toxicity:** Non-toxic to dogs and cats, according to the ASPCA (listed as Nephrolepis exalta bostoniensis). As with any plant, eating a lot of foliage can still upset a stomach.

## Good and bad

**Pros**
- Non-toxic to dogs and cats on the ASPCA list
- Full, arching fronds fill a basket, shelf or plinth cheaply
- Thrives in a bright, humid bathroom or kitchen with a window
- Needs no direct sun: bright, indirect light is enough
- Easy to find in Dubai and inexpensive in small sizes

**Cons**
- Fronds crisp and brown quickly in dry, air-conditioned rooms
- Soil must never dry out, so it needs frequent checking
- Scale and spider mites thrive in dry air (NC State)
- Dead fronds need trimming off regularly (RHS)

## Common mistakes

- Putting it in an air-conditioned living room by a vent. NC State says it needs high humidity, and scale and spider mites thrive in dry air.
- Letting the soil dry out between waterings. NC State says it should never dry out; this is a fern that wants steady moisture, not a ZZ plant.
- Misting as the only source of humidity. UNL Extension says you would have to mist every few minutes to change room humidity. Use a humidifier, group plants or choose a windowed bathroom.
- Treating the dark dots under the fronds as pests. NC State says they are spores, not insects.
- Standing it in a windowless bathroom. The RHS says bathrooms with no windows aren't suitable for live plants.

## Good to know

- The ASPCA lists Boston fern as non-toxic to dogs and cats. Eating any plant can still cause vomiting or an upset stomach.
- The RHS rates it H1B: it can summer outdoors in cool climates but needs indoor protection above 10 to 15°C. In a Dubai flat the issue is dry air and cold draughts rather than low temperature.
- If you run a humidifier, the EPA advises keeping indoor humidity below 60 per cent, ideally between 30 and 50 per cent, to avoid mould.
- On 7 October 2026 Plantsworld listed a 20 to 30 cm Boston fern from AED 41. Prices and sizes change.

## Using it in a garden

Roles: Bathroom shelf, Hanging basket, Kitchen windowsill, Humid grouping

A bright bathroom or kitchen with a window is the best room for Boston fern in a Dubai flat. The RHS says a bathroom with no window is not suitable for live plants, because plants need natural light. Hang it or stand it on a plinth where the fronds can arch freely, a metre back from tinted glass and out of the vent's airflow. If you only have a lounge, group it with other plants and run a humidifier in the room.

- [Bird's nest fern](https://plantguide.ae/plants/birds-nest-fern.md): A whole, glossy leaf beside Boston fern's finely cut fronds gives two textures from one plant family, and both like bright, indirect light and humid air.
- [Moth orchid](https://plantguide.ae/plants/moth-orchid.md): A white moth orchid adds a flower to the fern's green in a bright bathroom, and both are non-toxic on the ASPCA list.
- [Spider plant](https://plantguide.ae/plants/spider-plant.md): Spider plant is also non-toxic and far more tolerant of dry air, so it carries the shelf in the weeks the fern struggles.

## FAQ

**Why are my Boston fern fronds turning brown and crispy?**  
Most often dry air or dry compost. NC State says the fern needs high humidity and soil that never dries out, and the RHS names dry compost and cold draughts as dislikes. Check the soil first, then move the plant away from the vent, group it with other plants and add a humidifier. Trim dead fronds off at the base.

**Can a Boston fern live in a Dubai apartment?**  
Yes, if you give it the right spot: a bright bathroom or kitchen with a window is best. In an air-conditioned living room it needs a humidifier nearby and frequent checking. If that sounds like too much, choose a plant that ignores dry air, such as spider plant, which is also non-toxic.

**Is Boston fern safe for pets?**  
Yes. The ASPCA lists it as non-toxic to dogs and cats. Any plant can still upset a stomach if eaten in quantity.

**Does misting help a Boston fern?**  
Not much. UNL Extension says you would need to mist every few minutes to make a real difference to room humidity. A humidifier in the room works; grouping plants and a pebble tray help only locally.

**How much light does a Boston fern need?**  
Bright, indirect light (NC State, RHS). It tolerates shade but dislikes bright, direct sun (RHS), so a windowed bathroom or a spot well back from tinted glass suits it.

## Related plants

[Bird's nest fern](https://plantguide.ae/plants/birds-nest-fern.md) · [Spider plant](https://plantguide.ae/plants/spider-plant.md) · [Calathea](https://plantguide.ae/plants/calathea.md) · [Prayer plant](https://plantguide.ae/plants/prayer-plant.md) · [Nerve plant](https://plantguide.ae/plants/nerve-plant.md)

## Photos

![Botanical specimen in the Lyman Plant House, Smith College, Northampton, Massachusetts, USA.](https://upload.wikimedia.org/wikipedia/commons/4/42/Nephrolepis_exaltata_-_Lyman_Plant_House%2C_Smith_College_-_DSC04286.JPG)  
Photo: Daderot / CC0 / Wikimedia Commons ([source](https://commons.wikimedia.org/wiki/File:Nephrolepis_exaltata_-_Lyman_Plant_House,_Smith_College_-_DSC04286.JPG))

![Nephrolepis exaltata 'Bostoniensis'](https://upload.wikimedia.org/wikipedia/commons/1/1d/Nephrolepis_exaltata_%27Bostoniensis%27_%2849387866103%29.jpg)  
Photo: Dinesh Valke from Thane, India / CC BY-SA 2.0 / Wikimedia Commons ([source](https://commons.wikimedia.org/wiki/File:Nephrolepis_exaltata_%27Bostoniensis%27_(49387866103).jpg))

## Sources

- [RHS: Nephrolepis exaltata 'Bostoniensis'](https://www.rhs.org.uk/plants/58296/nephrolepis-exaltata-bostoniensis/details)
- [NC State Extension Gardener Plant Toolbox: Nephrolepis exaltata](https://plants.ces.ncsu.edu/plants/nephrolepis-exaltata/)
- [ASPCA: Toxic and Non-Toxic Plants — Boston Fern](https://www.aspca.org/pet-care/aspca-poison-control/toxic-and-non-toxic-plants/boston-fern)
- [RHS: Best bathroom plants for humid spaces](https://www.rhs.org.uk/plants/types/houseplants/best-bathroom-plants)
- [University of Nebraska-Lincoln Extension: Houseplant humidity](https://lancaster.unl.edu/houseplants-humidity)
- [US EPA: A brief guide to mold, moisture and your home](https://www.epa.gov/mold/brief-guide-mold-moisture-and-your-home)
- [Murtagh et al. (2022): Living with air-conditioning in Dubai, Chongqing and London — Buildings & Cities](https://journal-buildingscities.org/articles/10.5334/bc.147)
- [Wikipedia: Nephrolepis (family placement in the PPG I classification)](https://en.wikipedia.org/wiki/Nephrolepis)
- [Plantsworld: indoor plants collection (price, checked 7 October 2026)](https://plantsworld.ae/collections/indoor-plants)