Your Guide to Growing and Caring for Your Boston Fern

Graceful Boston fern plants are the hallmark of a classic front porch look. Boston ferns have a way of creating a welcoming and gracious style that is unmatched. Use them in hanging baskets or in large pots in your indoor garden. While caring for Boston ferns is not difficult, these plants have specific care guidelines that will help them flourish.

What is a Boston Fern?

Boston FernView in gallery

A Boston fern is a variety of sword fern that has gentle, draping fronds. The delicate fronds of the Boston fern make them a coveted variety. Boston ferns like all ferns are a variety of plant that reproduces via spores rather than seeds or flowers.

Fern spores are located on the back of the fronds, or leaves, and look like small brown spots. Boston ferns are not as finicky as other fern varieties and work well indoors. This makes them a popular houseplant, but they thrive well outdoors with the right climate conditions.

Boston Fern Care Details

Botanical nameNephrolepis exaltata
LightBright indirect light
Water

Water when the top of the soil dries out; Keep soil moist but not wet
Fertilizer

All purpose houseplant food at half strength every 4-6 weeks during the spring and summer
PestsSpider mites, mealybugs, scale insects, caterpillars, snails, slugs
DiseasesGraying nephrolepis, root rot
SoilWell draining soil mixed with peat moss and perlite
Climate ZonesHardy in Zones 9-11
Size12-24 inches
FoliageLarge, draping mid to light green leaves with multiple fronds
ToxicityNon-toxic for pets and humans

Caring for Boston Ferns

Boston ferns are a native of tropical forests. They thrive best under conditions that resemble these humid forests.


Boston Fern Light Needs

The Boston fern plant grows best in bright indirect sunlight as too much sun will burn the delicate fronds. Dappled morning sun is ideal as afternoon sun is hotter and can dry the soil too fast. Indoor plants also grow best away from direct sunlight. 

You should vary the fern’s location indoors in the winter and the summer as summer sun is much hotter. Rotate the position of the plant like you do with an indoor citrus tree to make sure that it is getting light on all its sides. This will ensure more even growth. Ferns do need ample light as too much shade does not produce healthy and full foliage.


Water Needs

The Boston fern prefers moist but not soggy soil. For indoor ferns, don’t allow the entire pot to dry out. Instead, just allow the top of the pot to dry before watering again. Make sure the roots never sit in excess water as this can cause root rot. You can avoid this with well-draining soil and a pot with good drainage holes. Be prepared to water your fern more often in the summer.

Make sure to keep outdoor ferns in hanging baskets and pots moist as well. In hot climates, you will need to water Boston ferns more often. You can cut back watering for indoor plants and outdoor plants that are overwintering inside. Water around once a month to keep plants from drying out. Water with room temperature water as cold water will shock the plant.


Soil Conditions

Boston ferns love a loamy soil that is enriched with some compost, peat moss, and perlite. This will create air pockets so that water will not pool around the roots. The soil should have a pH between 6.0 and 6.5. 

For outdoors plants, make sure that you don’t plant Boston ferns in soil with too much heavy clay. For a potted Boston fern, use a well draining soil enriched with peat moss and perlite. Make sure to use a pot with good drainage holes so that water doesn’t sit on the roots.


Atmospheric Conditions

Boston fern plants are tropical and love high humidity levels. The best Boston fern temperature is between 60-75 degrees Fahrenheit. While these plants love high humidity, they will adapt to levels of lower humidity. 

For a Boston fern plant that is indoors in dry conditions, raise the humidity with a humidifier. Also, sit potted ferns on trays of pebbles that you fill with water. Make sure that the water does not reach the roots of the plant. Mist indoor and outdoor plants on a regular basis to keep them looking lush.

Fertilizer

Boston ferns do not require as much fertilization as other plants. According to the horticulture experts at the University of Wisconsin-Madison, fertilize Boston ferns with an all purpose fertilizer. Fertilize with a half strength mixture once every 4-6 weeks during its growing season from spring through summer. 

Do not fertilize during the winter or after you have repotted a Boston fern. You need to give the fern 4-6 months to recover from the shock of the change before fertilizing again. The new rich soil will have enough nutrients to last for this time.


Pests and Diseases

If your plant begins to wilt and develop brown leaf tips or yellow fronds, inspect your plant for pests. Mealybugs, fungus gnats, and scales are common pest for Boston fern plants indoors. If you see bugs on your plant indoors, isolate the plant, prune off affected fronds, and place under running water. For outdoor plants, look for caterpillars, snails, and slugs. Treat indoor and outdoor plants with an insecticidal soap or neem oil solution.

Root rots and graying nephrolepis are some of the most common diseases for Boston fern plants. Prevent these by buying healthy plants and not overwatering. If you notice yellowing fronds, make sure the plants have good circulation and keep the soil drier.


Pruning

Boston fern plants do not require regular pruning. Feel free to remove broken or yellowed leaves that look unattractive.


Potting and Repotting Boston Fern Plants

Boston fern plants look amazing in pots on a front porch, a hanging basket, or as part of outdoor landscaping. If you live in a climate zone that isn’t suitable for these ferns, you will need to pot them for indoor use.

Use a pot that is at least 6 inches deep and one that is 1-2 inches larger than the root ball of the fern. This will give it room to grow. Once your fern does not have any more room in its current pot, repot in a larger pot to allow it to grow larger.


Boston Fern Propagation

Propagate Boston fern plants in two ways: divide the large plant or plant runners. To divide your plant, wait until the plant is dry, take a clean knife and cut the fern’s root ball into smaller sections. Repot each section in well-draining soil.

To plant runners, remove runners from the base of the fern and repot these runners.

Frequently Asked Questions (FAQ)FAQ

Where are there Boston ferns for sale?

Boston fern plants are available at a wide variety of stores. In the summer, find Boston ferns at local nurseries, but also at grocery stores and DIY stores. Wherever you buy your ferns, look for healthy plants that are free from pests, disease, and brown and yellow leaves.

How many Boston fern varieties exist?

According to the horticultural experts at the University of Florida, the exact number of Nephrolepis exaltata varieties is unknown. New varieties are forming and old varieties are lost all the time. Even so, there are around 50 varieties that are recognized as commercial varieties. Some of the most common varieties are Fluffy Ruffles Fern, Kimberly Queen Fern, Tiger Fern, Golden Boston, and Marisa.

Are Boston ferns toxic to cats and dogs?

Boston ferns are some of the few ferns that are not toxic to small animals or humans. If your cat or dog likes nibbling the Boston fern fronds, spray the plant with a mixture of water and vinegar to discourage this behavior.

How different is Boston fern care indoors and outdoors?

If you live in USDA growing zones 9-11, Boston fern plants can be grown outdoors. The best care they need is for you to make sure that they get enough water from the rain and fertilize as needed. If you don’t live in these climate zones, you need to bring your ferns to overwinter inside. Keep the humidity up, consistent moisture in the soil, and move plants away from heating vents that dry them out.

What companion plants look the best with Boston ferns?

Boston ferns look beautiful as a part of container gardens, other outdoor landscaping, or indoor gardens. Plants that look the best with Boston ferns are plants that work well in the shade. Look for astilbe, caladium, hostas, impatiens, and begonias to pair with Boston fern varieties.

Conclusion

Boston fern plants are an amazing variety of sword fern. While it may resemble its more fussy relation like the maidenhair fern, it is easier to grow and less particular about exact conditions. Beyond its beauty, others have touted the Boston fern for its indoor air purification benefits similar to the areca palm. Whatever the reason, Boston fern plants are wonderful for indoor or outdoor use. With just a minimum of care, you can keep these plants thriving and gorgeous.