Growing and Caring for Boston Ferns

Several lush fronds belong to a healthy Boston fern.
What You'll Need
Saucer with stones and water
Peat moss, sand, and garden soil
What You'll Need
Saucer with stones and water
Peat moss, sand, and garden soil

One of the most popular varieties of fern is the Boston fern. With its frilly leaves and long, hanging fronds, it's easy to see why it is so widely admired. Boston ferns that are full and flourishing make a wonderful addition to the home, adding an elegant charm and classic beauty unlike any other houseplant available.

Many people buy Boston ferns to adorn their decks and porches during the warm months of spring and summer. The Boston fern is closely related to the Sword fern, which is found growing wild in Florida and in the tropical regions around the Pacific Rim. They grow beautifully in humid locations that receive plenty of indirect sunlight, but when the threat of frost arrives in the fall, they must be brought indoors if they are to survive.

Tip: If the proper growing conditions are not provided indoors, the fern will react by shedding its leaves and will appear dull and lifeless. Some people give up on the fern after they notice it's not thriving indoors the same way it was outdoors. What is actually happening is the fern is having a difficult time adjusting to a lower humidity level, less light, and cooler temperatures. However, with proper winter care and the right growing conditions, a Boston fern will thrive through the cooler seasons and be ready to hang outside come next spring.

Ideal Growing Conditions

Many ferns, including Boston ferns, are native to sub-tropical and tropical rain forests. It is important that you mimic similar growing conditions the fern would have in the warm and humid forest.

While many ferns require shade to grow, the Boston fern is fond of lots of indirect light, like that which filters through the rainforest canopy. Place your Boston fern near a window that receives plenty of indirect sunshine. A bright east or west-facing window is an ideal location. They can endure dimly lit areas, but they won't flourish and grow.

Boston ferns prefer daytime temperatures that range from 65 to 75 degrees Fahrenheit, while evening temperatures should be a little cooler. Cooler temperatures reduce the chance of fungus developing, temperatures ranging between 55 and 65 being ideal. To adjust temperatures without making your home too cold, place your plant in a naturally cooler location in the home or in a room where heat vents can be closed. Also, keep in mind that areas closer to the ceiling are naturally warmer than lower levels. If your Boston fern hangs near the ceiling, check the temperature and adjust it if necessary. Otherwise, consider placing it in a sturdy plant stand or on a table.

Tip: The fern will grow fast in temperatures of 73 to 86 degrees Fahrenheit. Night temperatures are critical not only to keep fungus at bay but also for growth regulation.

Providing Humidity

Using a spray bottle to mist a plant

Rainforests are extremely humid environments and ferns are happiest when humidity is at least 50 percent. Because the humidity level inside a home is generally only 10 to 15 percent, it is important to provide supplemental humidity for your fern. When indoor temperatures rise above 70 degrees, you can provide your Boston fern with some of the humidity it requires by misting it on a daily basis. The humidity provided through misting is helpful, but it's not the complete answer. When the drops of water evaporate, so do the benefits.

During the hot months of summer, an indoor Boston fern on a table or stand can be placed on a saucer filled with stones and water. As the water evaporates, humidity is naturally provided to the plant. Simply fill a plant saucer with gravel, and then add water, stopping just below the top of the gravel. Place the pot on the gravel, and refill the saucer as necessary.

A humidifier is by far the best way to ensure your Boston fern receives the humidity it requires. For best results, run a humidifier in the room where your plant is located, especially during winter months when the air is warm and dry.

Consider buying a hygrometer to measure indoor humidity. This handy gauge will enable you to attain the correct level of humidity for the plant’s optimal health and vigorous growth. Hygrometers are available in many stores that sell outdoor thermometers, plants, and garden supplies.

Watering and Feeding

In warmer months during the growing season, provide your Boston fern with enough tepid water to keep the soil evenly moist, but not saturated. Water it more frequently during the hottest months of summer, and try not to let the soil become dry before watering. The foliage will lose its bright, green, healthy glow if it becomes too dry.

In the winter, allow the surface of the soil to become a little dry before watering. When new fronds begin to appear, start watering more often. Generally, you'll notice the appearance of new growth as the end of winter approaches.

During spring, summer, and fall, you will also want to apply a monthly dose of nitrogen-rich, water-soluble houseplant food, diluted to half the recommended strength.


It's not necessary to repot a Boston fern unless you want a larger plant. When the roots fill the pot, trim them to provide more space. You can also divide the root-bound plant into smaller plants, but choose containers wisely. The pot must be clean and have drainage holes in the bottom.

Tip: It's actually a good idea to repot a large fern, especially if it is pot bound, unless you want to water all the time.

The correct soil mix is essential to the health of the plant, too. To make a potting mixture suitable for Boston ferns, combine equal parts of peat moss, sand, and garden soil. Repot your plant, and care for it as directed.

With proper care and attention, your Boston fern will grow and thrive for many years to come.