The boston fern is one of the most recognisable and best loved houseplants in the world. Those lush, cascading fronds make a room feel alive the moment you hang one in a bright window. It also has a reputation for being difficult, and I understand why.
Boston ferns are one of those plants that look impossibly lush in photos and then immediately start dropping fronds the moment you bring them home. But once you understand what they actually need, everything changes.
This guide covers light, water, humidity, soil, feeding, the most common problems and a step by step revival plan. For more houseplant care guides and plant inspiration, visit PlantStyleHome.
What Is a Boston Fern?
The boston fern, Nephrolepis exaltata ‘Bostoniensis’, belongs to the Lomariopsidaceae family. Its wild relatives grow across the tropics of Central America, South America, Africa and Polynesia, usually on humid forest floors and alongside streams.
Keep that picture in mind. Nearly every care rule below comes from the fact that this plant is built for damp, shaded, steamy places.
The common name comes from Boston, Massachusetts, in the late 1800s. A shipment of unusual sword ferns arrived there, and gardeners noticed that one variety was far lusher and more vigorous than the rest. The name stuck.
How it grows:
- Arching, cascading fronds that can reach 60 to 90cm in length
- Spreads through runners, known as stolons
- Produces spores on the underside of the fronds, not flowers
- Lives indefinitely with good care, and can be divided again and again
Many people also love this plant for what it does for the air at home. It ranks among the top plants in NASA’s well known air purifying research, which found it helps remove formaldehyde and xylene from indoor air.
It is also non-toxic to cats and dogs. If you share your home with curious pets, that makes it one of the safest lush houseplants you can choose.
Popular varieties:
- ‘Bostoniensis’: the classic, and the one you will find most easily
- ‘Fluffy Ruffles’: compact, with ruffled frond edges
- ‘Tiger Fern’: striking variegated yellow-green fronds
- ‘Massii’: more upright, and slightly more tolerant of drier conditions
- ‘Compacta’: smaller and denser, good for tight spaces
Boston Fern Care: Light, Water, Humidity and Temperature
Good boston fern care comes down to four things. Get these right and most problems never appear.
Light
Bright, indirect light is ideal. A spot near a north or east facing window works beautifully.
Direct sun scorches the fronds and leaves crispy brown patches. Too little light is a quieter problem, producing slow growth and pale, thin fronds.
This fern tolerates lower light better than most flowering houseplants, but it will never look its best in a dim corner. Outdoors in summer, dappled shade under a tree is perfect. Full direct sun is never a good idea.
Boston Fern Watering
This is where many of us go wrong, myself included. I once let a gorgeous fern dry out over a busy week and watched it turn crisp within days.
Keep the soil consistently moist, but never waterlogged. The soil in a boston fern should never dry out completely, which means it needs watering more often than most houseplants.
- Press a finger about 2cm into the soil. If it feels dry, water right away
- Use room temperature water, because cold water shocks tropical roots
- Water thoroughly until it runs from the drainage holes, then let the excess drain fully
- Never leave the pot sitting in standing water
- Ease off slightly in winter when growth slows, but do not let the soil dry out entirely
If the fronds turn pale or slightly limp, check the soil first. Water is usually the culprit.
If you would like a tropical trailing plant that is far more relaxed about watering, our Pothos Plants guide covers one of the most adaptable and beautiful trailing plants you can grow.
Boston Fern Humidity
If I could pass on only one lesson, it would be this one. Humidity is the most critical factor in keeping this plant happy.
The ideal range is 50 to 80 percent. Most homes sit at 30 to 50 percent, and centrally heated homes can be even drier. No wonder so many ferns struggle.
Signs the air is too dry:
- Brown frond tips
- Fronds curling at the edges
- Yellowing and dropping fronds
- Small leaflets (pinnae) scattered across the floor
Ways to raise humidity:
- Use a humidifier nearby. This is the most effective solution by far
- Set the pot on a pebble tray filled with water
- Group plants together so they share moisture
- Mist the fronds in the morning, never in the evening, to avoid fungal problems
- Place the plant in a bathroom or kitchen, where showers and cooking add natural moisture
- Keep it away from radiators, heating vents and air conditioning
Another lush tropical plant that thrives in humidity is the cat palm. Our Cat Palm guide covers care, placement and how to keep its fronds beautifully green.
Temperature
Aim for 16 to 24°C (60 to 75°F). Below 10°C (50°F), fronds begin to die back. Above 27°C, heat combined with dry air causes a rapid decline.
Cold drafts, open windows in winter, air conditioning vents and radiators all trigger sudden frond drop. Pick a stable spot and leave the plant there.
If you love the lush, tropical look of this fern, our Monstera Plants guide covers another iconic tropical houseplant that thrives in similar conditions.
Soil, Pot and Feeding
Soil
Roots need air and moisture in equal measure. Heavy, compacted soil suffocates them, while a mix that drains too fast leaves the plant thirsty.
A recipe that has worked well for me:
- 60% peat-free potting compost
- 20% perlite
- 20% coir or fine bark
Aim for slightly acidic soil, around pH 5.0 to 5.5.
Pot
Plastic pots hold moisture longer than terracotta, which makes them the better choice for this plant. Drainage holes are essential.
A boston fern hanging basket is the traditional choice, and for good reason. It lets the fronds spill over the sides exactly as nature intended. Line the basket with coir fibre to keep moisture in while still allowing airflow.
Repot every one to two years in spring, once the roots completely fill the pot. Go up just one pot size.
If you love lush, trailing plants, our Spider Plant guide covers another brilliant and forgiving classic, perfect for hanging baskets and beginners alike.
Feeding
Feed every two to four weeks in spring and summer with a balanced liquid fertiliser diluted to half strength. Stop feeding in autumn and winter.
Too much fertiliser does more harm than good. Salts build up in the soil and burn both roots and fronds. Flush the pot with plain water every few months to wash them out.
Boston Fern Dropping Leaves: Causes and Solutions
Of all the problems people search for, this is the big one. A boston fern dropping leaves can feel like the plant is falling apart overnight.
Take a breath. Work through these causes in order, because the first is by far the most common.
1. Low humidity. Central heating and air conditioning dry the air quickly. Fix: raise humidity straight away with a humidifier, a pebble tray or a move to the bathroom.
2. Underwatering. Dry soil makes fronds drop fast. Fix: water thoroughly and check the soil more often.
3. Cold draft or temperature shock. Moving a fern from a warm shop to a cold car to a new room is a classic trigger. Fix: keep it in a stable temperature, away from drafts and windows.
4. Overwatering. Soggy soil leads to root rot, then yellow fronds, then drop. Fix: check the roots, and repot if they are brown and mushy.
5. Repotting shock. Dropping fronds after repotting is normal. Fix: stay patient, keep humidity high and water consistently. New growth will follow.
6. Natural shedding. Some lower fronds fall as the plant grows. If fresh fronds are emerging, your fern is healthy overall.
Boston Fern Turning Yellow: Why It Happens and What to Do
Yellow fronds are a distress signal, but the cause decides the fix. Look closely at where the yellowing starts and how the soil feels.
- Overwatering and root rot: yellowing moves from the base upward and the soil stays wet for days. Fix: remove mushy brown roots, repot in fresh mix and water less often
- Underwatering: fronds turn pale yellow, then dry out, and the soil is bone dry. Fix: water immediately and more regularly
- Low light: the colour looks washed out and the fronds grow thin and sparse. Fix: move to a brighter spot with good indirect light
- Nutrient deficiency: general yellowing during the growing season. Fix: begin a regular feeding routine with balanced fertiliser
- Natural ageing: the oldest fronds at the base yellow and die over time. Fix: simply cut them off cleanly at the base
How to Revive a Dying Boston Fern
If your fern looks completely brown and crispy, do not give up yet. Knowing how to revive a boston fern has saved several of mine that I had already written off.
Step by step revival:
- Cut back all dead brown fronds right to the base. Do not leave brown stubs.
- Check the root ball. Firm green or white roots are alive. If everything is brown and mushy, the rot may be too severe to recover from.
- Soak the root ball in lukewarm water for 30 minutes to rehydrate roots that have dried out completely.
- Repot into fresh, moist, well-draining compost.
- Place the plant in bright, indirect light.
- Build a humidity tent. Loosely cover the plant with a clear plastic bag for one to two weeks. This dramatically speeds up recovery.
- Keep the soil consistently moist but never waterlogged.
- Wait. New growth appears from the centre of the plant. Small curled fiddleheads within two to four weeks are your sign of recovery.
Prevention beats revival every time. Steady humidity and steady moisture are what keep this plant thriving.
Not everyone wants a plant that asks this much of them, and that is fine. If you want something lush that is far more forgiving of dry air and irregular watering, our ZZ Plant guide covers one of the most resilient plants you can grow indoors.
Boston Fern Outdoors: Summer Growing and Hanging Baskets
A boston fern indoors is lovely, but outside in summer it can be spectacular. Few plants fill a hanging basket as beautifully.
When to move it outside:
- Wait until after the last frost, when nights stay above 10°C (50°F)
- Acclimatise it gradually over one to two weeks so the fronds do not scorch
The ideal spot:
- Sheltered and shaded, such as dappled light under a tree, a covered porch or a north-facing wall
- Protected from strong wind, since the fronds are delicate
- Out of the direct afternoon sun
Hanging basket care outdoors:
- Water daily in warm weather, because baskets dry out fast
- Feed weekly with liquid fertiliser through summer
- Enjoy the natural humidity, especially after rain, which this plant loves
Bringing it back inside in autumn:
- Move it indoors before the first frost
- Inspect the fronds for pests first, especially spider mites
- Expect some frond drop while it adjusts. This is normal
Final Thoughts
The secret with a boston fern is not a green thumb. It is simply understanding that this plant is essentially asking to live in a rainforest, and doing your best to give it that.
Humidity and consistent moisture are everything. Get those two right, and you will have one of the most lush, dramatic and air-purifying plants you can keep at home.
If your fern is struggling right now, try the humidity tent trick from the revival steps above. It has rescued more of my plants than I can count, and I would love to hear how it works for you.
