Boston Fern Plant Profile

boston fern on a side table

The Spruce / Kara Riley

The Boston fern Nephrolepis exaltata 'Bostoniensis') is one cultivar of a fern species that can grow as tall as 7 feet in its native habitat. 'Bosoniensis' is a more demure variety, a well-known fern that has been long admired for its desirable traits as a houseplant. Boston ferns are attractive specimens with long, graceful fronds bedecked with tiny leaves. It is a relatively tough, easy to propagate fern that has a higher tolerance for light and dry conditions than other species. An added bonus is that Boston ferns can be displayed in any number of ways, including on pedestals, in hanging baskets, as part of a grouping, or as lush specimen plants on the right windowsill.

Boston fern is relatively trouble-free, but it can occasionally suffer from some of the same problems common to many indoor plants, including scale, mealybugs, and white flies. When grown outdoors, slugs can be a problem.

As hardy as this fern is, you still need to give it the proper care. Following a few simple growing tips will help guarantee a beautiful and vibrant houseplant you can be proud of.

Botanical Name Nephrolepsis exalta 'Bostoniensis'
Common Name Boston fern
Plant Type Herbaceous perennial fern
Mature Size 2 to 3 feet
Sun Exposure Part shade
Soil Type Moist, humusy, well-drained soil
Soil pH 5.0 to 5.5
Bloom Time Non-flowering
Flower Color Non-flowering
Hardiness Zone 10 to 12
Native Area Tropical regions in Americas, Africa, Polynesia
closeup of a Boston fern
The Spruce / Kara Riley 
Boston fern from above
The Spruce / Kara Riley 
closeup of Boston fern
The Spruce / Kara Riley 

How to Grow Boston Ferns

Nephrolepis ferns appreciate a little TLC. They like to be kept in warm, humid conditions and don't appreciate being blasted by air from windows or heating/air conditioning vents. Remove dead fronds and occasionally rotate the plant to keep it growing evenly. During the winter when the plant isn't growing, you can reduce watering, but your fern should never be allowed to completely dry out. Make sure to maintain a balance of elements for best results—as is true for most plants, growing ferns is all about moderation and a sober approach that doesn't overemphasize any one element.

Light

The Boston fern needs bright indirect light when grown indoors (outdoors, it prefers denser shade). Some species of the Nephrolepis genus can be trained to handle almost full sun, but most species, including the N. extensis 'Bostoniensis' cultivar, prefer filtered, dappled light.

Soil

Boston ferns need a loamy, rich, organic mixture as a potting soil. Make sure the drainage is good to avoid rotting the roots, which will be evident if the plant is beginning to lose leaves or appears waterlogged. It's a good idea to choose a soil that contains some organic material.

Water

It is important to keep the root ball moist at all times. If your Boston fern is sitting in a somewhat dry area (instead of humid), mist with water frequently to keep moist.

Temperature and Humidity

These ferns can survive the occasional blast of cold, down to 50 degrees Fahrenheit or even slightly colder for a few hours. However, they really thrive between 60 and 75 degrees. Boston fern grown indoors prefers humidity no lower than 80 percent; in environments drier than this, it should be frequently misted.

Fertilizer

During the growing season, feed the fern with liquid or slow-release pellets. If you're not happy with the fern's progress, it won't hurt to slightly increase the fertilizer within reasonable limits.

Potting and Repotting

In the spring, you should repot into fresh compost, even if your Boston fern hasn't outgrown its pot and it's not necessary to move up in pot sizes. Common signs that a plant needs repotting include overcrowding and wilting leaves, so keep an eye on your Nephrolepis for any telltale signs of stress—failure to repot these plants could cause death. This is also a good time to divide plants and multiply your collection.

Propagating Boston Fern

Boston ferns are very easy plants to propagate—simply divide the plant while repotting in the spring. Even very small divisions will root if care is taken with them (meaning plenty of warmth and humidity). Make sure each division has a section of healthy roots. Ferns can also be propagated by spore, but this is somewhat more difficult.

Related Cultivars

  • Nephorolepis exalta 'Compacta': a shorter, more compact and more upright version
  • Nephorolepis exalta 'Florida Ruffle': a medium-sized cultivar with feathery, ruffled fronds.
  • Nephorolepis exalta 'Golden Boston': similar to Boston fern, but with yellow-green fronds.
  • Nephorolepis exalta 'Rita's Gold™': a more compact plant with chartreuse fronds
  • Nephorolepis exalta ‘Fluffy Duffy’: a smaller, denser fern with fine-textured, feathery fronds
Boston fern leaf texture
The Spruce / Kara Riley