Boston fern
Nephrolepis exaltata
Foliage and indoor
- Light
- Part sun, Shade or indoors
- Pot size
- Medium pot (about 5 to 15 litres)
- Care level
- Easy
- Year round or seasonal
- Kept year to year; in a pot, keep it above about 15.6 °C (60 °F)
- Pets
- ASPCA: non-toxic to cats and dogs
Light and position
Bright, indirect light; listed for dappled light and deep shade.
Size and pot
NC State lists 2 to 3 feet tall and wide. Our pot band: medium pot (about 5 to 15 litres).
Watering
Keep the soil moist and never let it dry out, but cut back in winter when the plant rests, as overwatering then causes root rot.
Potting mix and feeding
Well-drained, loamy mix. Humid spots such as near a kitchen or bathroom suit it, or stand the pot on a tray of wet pebbles.
Growing through the year
NC State notes it can become invasive in warm climates if it escapes into the ground.
Winter outdoors
Cold limit in a pot: about 15.6 °C (60 °F). NC State says to give it warmth of 60 to 70 °F; we use the bottom of that range, 60 °F, as its limit.
| Your coldest winter nights | What to do |
|---|---|
| Coldest nights 15 °C or warmer | Move it to shelter before nights fall to 15.6 °C |
| Coldest nights 10 to 15 °C | Move it to shelter before nights fall to 15.6 °C |
| Coldest nights 5 to 10 °C | Move it to shelter before nights fall to 15.6 °C |
| Coldest nights 0 to 5 °C | Move it to shelter before nights fall to 15.6 °C |
| Light frost: nights down to about −5 °C | Move it to shelter before nights fall to 15.6 °C |
| Hard frost: nights below −5 °C | Move it to shelter before nights fall to 15.6 °C |
A plant can stay out only when its limit is below the coldest night in your band; a limit equal to that night counts as needing shelter. A rare cold snap, wind or a wet pot can still damage plants. We convert °F to °C with NIST’s formula.
Watch for
Scale and spider mites when the air is too dry.
Pets and people
ASPCA lists Boston fern as non-toxic to dogs and cats.
General gardening information, not professional advice. Plant toxicity details are a starting point, not veterinary or medical advice: if a pet or child may have eaten a plant, contact a veterinarian or doctor promptly.
Care level: NC State’s maintenance rating (Low). Pot band and summary wording are ours, based on the sources below.