Boston Fern

By Plant Liker •  Updated: 09/10/20 •  4 min read
Boston Fern air purifier

Boston Fern (Nephrolepis exaltata “Bostoniensis”) is a type of Sword Fern, also known as the Boston sword fern, wild Boston fern, Boston Blue Bell Fern, tuber ladder fern, or fishbone fern. Verona fern is a three-pinnate variety of Boston fern, probably the best of the lace varieties for indoor growing.

What characteristics have these ferns that make them the most successful of all house plants?

Simply put: they look good and are long-lasting beauties.

Beautiful all year round and treasured for its lush foliage — which reaches a height of 4 feet and a spread of 5 feet, this fern does not grow flowers; instead of colourful flowers, it boasts feathery fern leaves which are best displayed as a hanging plant. And because it does not waste its energies on extravagances, the fern will last in your house for much longer than flowering plants.

Your aim should be to make your fern’s environment approximate to its native habit as possible. The resulting plant will be a combination of three things: the individuality of the plant itself, the environment you’ve created for the plant, and your own personality.

Benefits: The Boston Fern is effective at removing formaldehyde and for adding humidity to the indoor environment.

Boston Fern Care

  1. Water regularly, a little every day. Do not let your plant become dried out. A parched fern looks gray and dull, and droops. Do not keep the soil so wet that it is muddy. When a fern has “wet feet” continually, its leaves turn yellow.
  2. Keep the temperature moderate, not over 70 and not under 50. Ventilate the room if gas is used, but do not let the fern sit in a drafty area.
  3. Clean the leaves if they become dusty or buggy. The leaves are best washed when the air is such that they will dry off quickly. but not burn in the hot summer sun.
  4. Give your fern the best light in the house if you really want it to be happy. Ferns like direct sunlight only if the air is kept humid, which isn’t always possible in your house. Found on the forest floor protected by larger trees, it makes sense that ferns prefer indirect sunlight to semi-sun environments. Do not rotate your fern with the idea of making it develop symmetrically; all the new leaves will be underdeveloped, and only those exposed to the light will benefit at any one time.
  5. If your fern is happy and all these care requirements are met, the Boston fern will grow until it becomes root bound (and no, ferns do not like to be root bound in a pot too small for their potential). Repotting is best done in late spring (May or June), and if the plant can then be plunged into the soil outdoors, pot and all, in a shady corner of the yard, your fern will reinvigorate itself. During the year, fertilizer may be given in the form of weak sodium nitrate solution, Clay’s fertilizer, or any leaf food (ferns are not flowering plants, recall).

Quick Summary of FAQs

Fertilizer and Water

Feed weekly with a weak liquid fertilizer. Feed infrequently in winter; preferably use rain water to keep the soil moist but not soggy.  Water should be room temperature and free of chlorine and fluoride. (Boston ferns are sensitive to water temperature and chemicals). 


This plant is relatively hardy, though when it isn’t cared for properly, it can be prone to spider mites and whitefly pests, which can be controlled using a soapy water spray. Inspect new plants for bugs before bringing them home.

Boston Ferns and Brown Leaves: Causes, Prevention, and Solutions

Being a forest dweller, your fern must have frequent misting and watering, or the leaves will brown and drop.

Be Gentle: Do not touch or move Boston ferns too vigorously: bumping walls, people or pets will cause the leaves to brown. Not a kid-friendly plant.

Best Soil for Growing Sword Ferns or Boston Ferns

Think about where you find ferns in forests: in damp, slightly acidic soil, in shaded areas, typically. Mimic those soil conditions and you’ll have a happy plant.

Soil should be well-drained, with an organic topsoil of humus and small stones to mimic the fern’s natural growing conditions. These ferns prefer an acidic soil with sand and humus. (You can utilize a pH test kit to make sure your soil is in the right range). Sword ferns can grow well in acidic soil (pH 5.6 to 6.0), but do better with a mildly acidic soil pH of 6.1 to 6.5, for both indoor and outdoor planting.

Boston ferns, like other houseplants, will grow to the size of their pot, at which point they will need repotting, or will slowly deteriorate.

Plant Liker