Encyclopedia of Houseplants

Boston Ferns: An Easy-to-Grow, Non-Toxic Classic

updated Oct 25, 2022
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(Image credit: Apartment Therapy)

If you’re craving the frilly greenery of a fern, but don’t quite feel up to taking care of a high-maintenance diva like the maidenhair fern, then a Boston fern might be perfect for you. These puffy plants are interior classics for a reason, earning their decades of popularity by being one of the easiest ferns to care for and maintain.

About Boston Ferns

The Boston fern, or Nephrolepis exaltata ‘Bostoniensis,’ is a type of sword fern that originated in humid forests and swamps. Its distinctive arching fronds are a mutation from the straight fronds of standard sword ferns. The popular stories are that the mutation either occurred on a ship full of ferns being sent to Boston or in the plant nursery of a Florida grower who later sent them to friends in Boston.

According to the ASPCA, Boston ferns are non-toxic to dogs and cats, much like the Lemon Button Fern.

(Image credit: Natalie Jeffcott)

Where to Grow

Their natural habitat of dappled shade means that Boston ferns do best with lots of indirect light. They prefer standard room temperature, 55 to 75°F (13 to 24°C), although they do best on the lower end of that range, meaning that you should try to keep yours in the coolest spot in your home.

Boston ferns love humidity, but the standard 10 to 15% humidity of most homes is a far cry from the 50%-or-greater humidity that these plants prefer. Solutions include keeping your fern in a steamy bathroom, placing it on a water-filled pebble tray, using a humidifier, and/or daily misting. Brown leaf tips and yellowing are signs of too little humidity.

Boston ferns are mainstays of hanging baskets on balconies and porches, but except in USDA zones 9 through 11, they need to be brought indoors in the winter. Before you bring your plant indoors, give it a good pruning to remove all but the healthiest fronds, and gradually acclimate it to the indoor environment.

If you don’t have the right spot for an overwintering fern in your home, you can keep it in a dormant state in a dark garage, basement, or shed where the temperature stays above 55°F (13°C). Water once a month to keep the plant from completely drying out. When spring arrives, cut back dead foliage, and keep it well-watered to allow the fern to regenerate.

Credit: Hannah Puechmarin

Care and Planting

Especially during the spring and summer growing months, keep your fern’s soil moist, but not soggy. Slightly reduce watering during the winter (unless you’re overwintering in a dark area, see above). A self-watering pot is a good way to keep your fern’s soil moist, but you can also keep it in a plastic pot (inside a prettier cachepot) to help it stay hydrated. Pot in a rich soil high in peat moss.

If your fern does briefly dry out and the fronds turn brown and die, you can probably revive it by cutting off all of the dead foliage at ground level and keeping the soil moist while it regenerates.

Fertilize with diluted half-strength liquid fertilizer monthly from spring to early fall.

A pot-bound fern will be difficult to keep well-watered, so when the roots fill the pot, you can divide your fern into smaller plants. Spring is the best time to divide or repot. Let the soil dry out slightly, then remove the plant from its pot, and slice the roots apart with a serrated knife. Place each new plant in its own pot with fresh soil, and water well.