📘 Nephrolepis exaltata – Mindat.org
📘 Boston Fern (Nephrolepis exaltata ‘Bostoniensis’) – University of Wisconsin-Extension Horticulture.
📘 Boston Fern Production Guide – University of Florida IFAS Extension.
Caring for the Boston fern or Fishbone fern (Nephrolepis exaltata) is not too difficult with proper care. This graceful, arching plant with lush green fronds thrives with high humidity similar to its native habitats in humid forests and swamps from northern South America to Mexico and Central America.
For the best Boston fern care at home, provide bright, indirect light and consistently moist soil that is never soggy. Mist the fern daily or place its pot on a pebble tray to recreate the humid environment this classic houseplant loves. With the right Boston fern care, this sword fern will continue gracing any indoor space with a touch of the tropics and fresh, vibrant foliage.
🪴 In This Article 🪴
💚 Care
📃 Types
🪴 Potting
✂️ Pruning
🌱 Propagating
🐛 Pests
🩺 Problems and Diseases
❓ FAQ
👀 Overview
Boston ferns are evergreen plants that can grow up to 3 feet tall and wide, with fronds that can reach up to 4 feet long. They are known for their sword-shaped, blue-green foliage, which contains tiny leaflets that grow erect and arch gracefully as they mature.
Boston ferns are relatively easy to care for, making them a popular choice for indoor gardening. They thrive in bright, indirect light, high humidity, and consistently moist soil.
| 📖 Common name | Boston Fern, Sword Fern, Fishbone Fern, Boston Sword Fern |
| 🔬 Botanical name | Nephrolepis exaltata |
| 🫴 Care Difficulty level | Easy to Moderate |
| ☠️ Toxicity | Non-toxic to pets and humans |
| 💨 Air-purifying Qualities | Excellent |
| 🌱 Soil Type and pH | Well-draining, slightly acidic to neutral |
| ☀️ Sun Exposure | Bright, indirect light |
| 🍪 Edibility | Not edible |
| 🌴 Plant type | Fern |
| 🍃 Foliage Type | Evergreen |
| 🌿 Color of leaves | Bright to dark green |
| 🌸 Flower color | N/A |
| 💥 Bloom time | Does not bloom |
| 🚀 Growth Speed | Moderate |
| 📏 Mature Size | Up to 3 feet wide, fronds can be 2-3 feet long |
| 🔄 Life Cycle | Perennial |
| 🌍 Hardiness zones | 10-12 (Indoors in colder climates) |
| 🗺️ Native area | Tropical and subtropical regions worldwide |
💚 Boston Fern Care
To ensure the healthy growth of your Boston fern indoors, it’s essential to provide the right growing conditions. This includes placing the fern in a location with indirect sunlight, maintaining high humidity levels, and keeping the soil consistently moist.
Regularly inspect your fern for signs of pests or diseases, and follow the care tips provided in this guide to address any issues that may arise. With proper care and attention, your Boston fern can thrive and bring a touch of natural beauty to your indoor space.
☀️ Light ☀️
Boston Ferns thrive in bright, indirect light. They should be placed in a spot that receives 2-3 hours of morning or late afternoon sunlight daily. Avoid direct sunlight, which can burn and damage the fronds.
The ideal light levels for Boston Ferns range from 10,000-12,000 lux. You can measure the light intensity with a light meter.
Indoor Lighting
When growing Boston Ferns indoors, place them 4-6 feet away from an east, west, or north facing window. This provides bright, indirect light without risk of scorching.
Southern windows can also work if filtered with a sheer curtain. Make sure to rotate the plant weekly for even growth.
Outdoor Lighting
Outdoors, Boston Ferns do best in bright, dappled shade. Good locations include under a patio cover, porch, or lath house.
Morning sun and afternoon shade is ideal. Avoid direct sunlight between 10am-4pm when light is most intense.
Signs of Insufficient Light
- Slow growth
- Smaller fronds
- Fronds turning yellow or brown
Signs of Excessive Light
- Dry, brown leaf tips
- Burnt, crispy fronds
By providing the proper level of bright, indirect light, you can keep your Boston Fern healthy and vibrant. Monitor closely and adjust the lighting as needed through the seasons. Proper lighting is crucial for lush, vigorous growth.
💧 Water
Boston Ferns require consistent moisture and should never be allowed to dry out completely. To maintain the right moisture levels, follow these guidelines:
Watering Frequency
- Water your Boston Fern 1-2 times per week during the growing season (spring and summer) .
- In winter, reduce watering frequency, allowing the top 1-2 inches of soil to dry out between waterings.
Watering Technique
- Use lukewarm water to avoid shocking the plant.
- Water the plant thoroughly, ensuring the soil is completely damp but not soaked.
- Allow the plant to drain properly and never let the pot stand in water to prevent root rot.
Signs of Overwatering and Underwatering
Overwatering:
- Yellowing leaves
- Wilted leaves
- Root rot
Underwatering:
- Dry, crispy leaves
- Shedding leaves
- Slow growth
Tips for Maintaining Proper Moisture
- Check the soil moisture regularly by touching the surface with your fingertip. If it feels slightly dry, it’s time to water the plant.
- Use a well-draining potting mix to prevent waterlogged soil.
- Increase humidity around the plant by placing it on a tray filled with pebbles and water, using a humidifier, or misting the plant with room-temperature water.
Remember that the frequency and amount of water required may vary depending on factors such as the size of the pot, the type of potting mix, and the environment (temperature and humidity). Adjust your watering routine accordingly to ensure the best care for your Boston Fern.
🪴 Soil
Boston Ferns thrive in a lightweight, porous, and fast-draining soil mix with acidic pH between 5.5-6.5. The ideal soil mix should retain moisture but not get waterlogged.
Recommended Soil Mix
A good basic soil mix for Boston Ferns consists of:
- 1 part peat moss or coco coir for moisture retention
- 1 part perlite or vermiculite for drainage
- 1 part potting soil for nutrients
You can also use a pre-mixed indoor potting soil or an orchid mix.
Acidic pH
Maintain the soil pH between 5.5-6.5 by incorporating organic matter like compost, peat moss, oak leaves, or pine needles.
You can test the pH with a soil test kit and amend the soil with elemental sulfur or aluminum sulfate if needed to lower pH.
Moisture
The soil should be kept consistently moist but not soggy. Allow the top 1-2 inches of soil to dry out between waterings.
Use your finger to check moisture levels and water thoroughly until it drains from the bottom when the top layer feels dry.
Indoors vs Outdoors
For indoor Boston Ferns, use a well-draining indoor potting mix. Outdoors, incorporate compost and organic matter into native soil before planting.
Provide proper soil moisture and drainage for healthy, vigorous Boston Ferns indoors or outdoors.
🍼 Fertilizer
Fertilizing Boston Ferns during their active growing season is important to maintain healthy growth and prevent nutrient deficiencies.
- Use a balanced, water-soluble houseplant fertilizer with an NPK ratio of 20-20-20 .
- Dilute the fertilizer to half strength before applying to avoid fertilizer burn.
- Fertilize every 2-4 weeks during the spring and summer growing season.
- Discontinue fertilizing in the fall and winter when growth slows down.
- Alternately, use slow-release fertilizer pellets applied in the spring, which provide nutrients for 6-8 weeks.
- For organic options, use compost tea, fish emulsion, or liquid kelp .
Signs of Nutrient Deficiency:
- Yellowing or pale leaves
- Slow growth
- Leaf drop
By fertilizing at the right time with an appropriate fertilizer, you can keep your Boston Fern healthy and thriving indoors. Monitor the plant closely and adjust your fertilizer regimen as needed.
🌡️ Temperature
Boston Ferns prefer a temperature range of 60-75°F (15-24°C) for optimal growth. They can tolerate temperatures as low as 50°F (10°C) and as high as 95°F (35°C), but prolonged exposure to these extremes can cause stress and damage to the plant.
Indoor Temperature
When growing Boston Ferns indoors, maintain a consistent temperature within the ideal range. Avoid placing the plant near cold drafts, heating vents, or air conditioning units, as sudden temperature fluctuations can harm the plant.
Outdoor Temperature
If you live in a region with mild temperatures, you can place your Boston Fern outdoors during the warmer months. However, bring the plant indoors when nighttime temperatures drop below 50°F (10°C) to protect it from cold damage.
Signs of Temperature Stress
- Browning or drying leaves (too hot or too cold)
- Wilted leaves (too cold)
- Slow growth (too cold)
By maintaining the proper temperature range and avoiding sudden fluctuations, you can ensure a healthy and thriving Boston Fern. Monitor the temperature closely and adjust the plant’s location as needed to provide the best possible environment.
💦 Humidity
Boston Ferns thrive in high humidity levels, ideally between 60-70% or higher. Maintaining proper humidity is essential for the health and appearance of the plant.
Increasing Humidity
To create a more humid environment for your Boston Fern, consider the following methods:
- Misting: Mist the plant with room-temperature water 1-2 times a day.
- Pebble tray: Place the plant on a tray filled with pebbles and water, ensuring the pot is not sitting directly in the water.
- Grouping plants: Group Boston Ferns with other humidity-loving plants to create a microclimate with higher humidity levels.
- Humidifier: Use a humidifier to increase the humidity in the room where the plant is located.
Signs of Low Humidity Stress
- Brown or dry leaf tips
- Yellowing leaves
- Leaf drop
By maintaining the proper humidity levels, you can ensure a healthy and thriving Boston Fern. Monitor the humidity closely and adjust your methods as needed to provide the best possible environment for your plant.
📃 Types of Boston Fern
There are many different cultivars and varieties of Boston Ferns available. Some of the most popular include:
- ‘Bostoniensis’ – The classic green Boston Fern with gracefully arching fronds. This is the most common variety grown indoors.
- ‘Dallas’ – More compact and upright growth habit with dark green fronds.
- ‘Fluffy Ruffles’ – Feathery, ruffled fronds that grow densely. Also known as ‘Florida Ruffle’.
- ‘Kimberly Queen’ – Finely dissected, delicate fronds that create an airy appearance.
- ‘Rita’s Gold’ – Yellow-green colored fronds, lighter than the classic green.
- ‘Tiger’ – Variegated fronds with yellow stripes along the pinnae.
- ‘Roosevelt’ – Twisted and wavy fronds that are deeply divided.
- ‘Teddy Junior’ – More compact growth and twisted fronds.
While care is similar across varieties, some are better suited for certain conditions. For example, ‘Dallas’ and ‘Teddy Junior’ tolerate heat and dryness better than classic ‘Bostoniensis’. When selecting a Boston Fern, consider factors like available space, light levels, and desired appearance. With proper care, most varieties can thrive indoors.
Blooming and Flowers
Boston Ferns (Nephrolepis exaltata) are primarily grown for their lush, green foliage, and they are not known for producing showy flowers. However, they do produce spores, which are essential for their reproduction process.
Blooming Season
Boston Ferns produce spores throughout the year, with many varieties releasing spores in spring, summer, fall, and winter.
Flower Appearance
Since Boston Ferns do not produce flowers, their reproductive structures are found on the fronds in the form of spore-producing sori. These sori appear as small, brown or black dots on the underside of the fronds.
Spore Production
Spores are single cells that play a crucial role in the fern’s life cycle. When the spore capsules on the underside of the frond are brown and mature, they release spores that can be used for propagation.
🪴 Potting and Repotting Boston Fern
Boston Ferns benefit from repotting every two to three years to provide fresh soil and accommodate their growing root system. Repotting is best done in spring when the plant is actively growing. Follow these steps for successful potting and repotting:
Preparing for Repotting
- Water the plant a couple of days before repotting to ensure the soil is moist and clings to the roots.
- Choose a new pot that is 1-2 inches (2.5-5 cm) larger in diameter than the current pot. Make sure it has drainage holes to prevent waterlogging.
Potting and Repotting Process
- Fill the new pot with 2-3 inches (5-8 cm) of fresh potting soil. Use a well-draining soil mix, such as a combination of potting soil, peat moss or coco coir, and perlite or vermiculite.
- Carefully remove the Boston Fern from its current pot, preserving as much of the root system as possible.
- If the plant is root-bound, gently loosen the roots and trim any tangled or damaged sections.
- Place the fern in the new pot, ensuring the top of the root ball is slightly below the rim of the container.
- Fill in around the root ball with more potting mix, pressing gently to eliminate air pockets.
- Water the plant thoroughly, allowing it to drain completely before placing it back in its permanent location.
Dividing Boston Ferns
If your Boston Fern has become too large, consider dividing it during the repotting process. Use a sharp knife to cut the root ball into halves or quarters, keeping the foliage intact. Repot each division into a separate pot with fresh potting soil.
By repotting your Boston Fern as needed, you can ensure its continued health and growth. Monitor the plant closely and adjust your potting and repotting schedule based on its growth and overall appearance.
✂️ Pruning Boston Fern
Pruning Boston Ferns is essential for maintaining their shape, promoting healthy growth, and removing dead or damaged fronds. Regular pruning also helps prevent pests and diseases from spreading. Follow these guidelines for successful pruning:
When to Prune
- Perform routine trimming of discolored and unattractive foliage at any time.
- Conduct severe pruning in spring or summer, ideally during repotting.
Pruning Techniques
- Use clean, sharp pruning shears or scissors to prevent the spread of diseases.
- Remove dead, discolored, or irregularly shaped fronds at the base of the plant.
- Trim side fronds to maintain the plant’s shape and control its size.
- Avoid cutting the top of the plant.
- Do not remove more than 1/3 of the foliage at once.
Encouraging New Growth
Severe pruning can encourage more prolific, bushy growth and correct dull, leggy growth. After pruning, new fronds will emerge, and the plant will regain its lush appearance within a few weeks to months.
Tips for Successful Pruning
- Prune during the active growing season (spring and summer) for the best results.
- Monitor the plant closely and adjust your pruning schedule based on its growth and overall appearance.
- Be patient, as it may take some time for the plant to recover and produce new growth after severe pruning.
By pruning your Boston Fern regularly and following the proper techniques, you can maintain its health and appearance, ensuring a thriving and attractive indoor plant.
🌱 How to Propagate Boston Fern
Boston Ferns can be easily propagated from spores, rhizome division, or by separating rooted plantlets. Follow these steps for successful propagation:
Propagating from Spores
Spores are found on the underside of mature fronds.
- Use a paper envelope to collect spores once they appear brown and powdery.
- Sow spores thinly on the surface of a sterile potting mix. Use a mix of peat moss, vermiculite, and perlite.
- Cover the pot with plastic wrap and place in bright, indirect light.
- Keep the soil moist but not soggy. Germination can take 2-3 months.
- Once prothalli (young gametophyte plants) develop, remove the plastic wrap. Keep soil moist and mist frequently.
- When small ferns develop, transplant them into individual pots with potting mix.
Propagating by Division
- Carefully divide the fern at the root ball into smaller sections using a sterilized knife.
- Ensure each division has some roots and fronds attached.
- Repot the divisions into small pots using a well-draining potting mix.
- Water thoroughly after repotting and place in filtered light.
Propagating from Plantlets
- Look for plantlets growing on older fronds near the soil.
- Once plantlets have developed small roots, carefully detach them from the frond.
- Pot the plantlets in small pots filled with potting mix.
- Keep warm and humid, watering frequently but avoiding soggy soil.
🐛 Common Pests
Boston ferns are generally low-maintenance plants, but they can sometimes be affected by pests. In this section, we will discuss the common pests that can infest Boston ferns and how to deal with them effectively.
1. Mealybugs
Mealybugs are small, white, fluffy insects that can cluster on the stems and leaves of your Boston fern. They feed on the plant’s sap, which can cause stunted growth and yellowing leaves. To treat mealybugs:
- Isolate the affected plant
- Remove any visible insects with a cotton swab dipped in rubbing alcohol
- Use an insecticidal soap or neem oil spray to kill any remaining bugs
2. Caterpillars
Caterpillars, such as the Florida fern caterpillar, can infest Boston ferns and cause damage by feeding on the leaves. To control caterpillars:
- Handpick caterpillars from the plant and drop them into a bucket of soapy water
- Spray the fern with a product containing Bacillus thuringiensis (B.t.), a natural bacteria that targets caterpillars
3. Fern Mites
Fern mites are tiny pests that can cause yellowing and webbing on the leaves of your Boston fern. To treat fern mites:
- Isolate the affected plant
- Spray the fern with a miticide or insecticidal soap, ensuring thorough coverage of the leaves
4. Scales
Scale insects are small, flat insects that can attach themselves to the stems and leaves of your Boston fern. They feed on the plant’s sap, which can cause yellowing and wilting of the leaves. To treat scale:
- Isolate the affected plant
- Gently wipe the leaves with a damp cloth to remove any visible insects
- Apply an insecticidal soap or horticultural oil to kill any remaining scales
5. Thrips
Thrips are tiny insects that can cause damage to Boston ferns by feeding on the plant’s sap. To control thrips:
- Inspect your fern regularly for signs of thrips, such as discolored or distorted leaves
- Use yellow or blue sticky traps to monitor and catch adult thrips
- Apply insecticidal soap or neem oil to control thrips populations
In conclusion, regularly inspecting your Boston fern for signs of pests and providing optimal care can help prevent infestations. If you notice any pests, take prompt action to treat the issue and protect your fern’s health.
🩺 Common Problems With Boston Fern
Boston ferns are generally easy to care for, but they can be susceptible to a few common problems. Here are some of the most common issues and how to treat them:
- Root Rot: Root rot is a fungal disease that can affect your Boston fern if it is overwatered or if the soil does not drain well. It can cause the roots to rot, which can lead to yellowing and wilting of the leaves. To treat root rot, remove the affected plant from its pot and inspect the roots. If they are brown and mushy, carefully trim away the affected areas and repot the plant in fresh soil. Be sure to allow the soil to dry out slightly between waterings to prevent future infections.
- Dry, Curled Foliage: Dry, curled foliage is usually a sign of underwatering or low humidity. To prevent this issue, keep the soil evenly moist and maintain high humidity levels by using a room humidifier, keeping the pot on top of pebbles in a tray filled with a little water, or misting often.
- Pests: Boston ferns can be vulnerable to pests like mealybugs, scales, fungus gnats, and caterpillars. Inspect your fern regularly for signs of pests and treat any infestations promptly using insecticidal soap, neem oil, or other appropriate methods.
- Leaf Drop: Boston ferns may drop leaves due to underwatering, low humidity, temperature stress, nutrient deficiency, or aging. To address these issues, ensure proper watering, maintain high humidity, keep the plant in a stable temperature range, provide necessary nutrients, and remove older fronds as needed.
- Fungal Diseases: Boston ferns can be affected by diseases like powdery mildew and leaf-spot disease. To help prevent these, avoid overwatering, let the soil dry out slightly between waterings, and maintain good air circulation around the plant.
To keep your Boston fern healthy and thriving, it’s essential to address these common problems promptly. Regularly inspect your fern for signs of pests or diseases, and take steps to maintain proper watering, humidity, and temperature conditions. With proper care and attention, your Boston fern can continue to grow and thrive indoors.
🖼️ Display Ideas
Boston ferns are versatile and can be displayed in various ways to enhance your indoor space. Here are some creative display ideas to showcase your Boston fern:
- Hanging Baskets: Boston ferns look stunning when placed in hanging baskets, allowing their fronds to cascade gracefully. Hang them near a window with bright, indirect light or in a shaded area of your patio or porch.
- Plant Stands: Elevate your Boston fern by placing it on a plant stand. This not only adds height to your display but also allows the fern’s arching fronds to create an eye-catching focal point.
- Shelves and Bookcases: Incorporate Boston ferns into your home decor by placing them on shelves or bookcases. Their lush green foliage can add a touch of nature and soften the look of your space.
- Grouping with Other Plants: Create a mini indoor garden by grouping your Boston fern with other plants that have similar light and humidity requirements, such as other fern varieties, pothos, or peace lilies.
- Decorative Containers: Choose a decorative container or pot that complements your interior design style. This can add an extra layer of visual interest to your Boston fern display.
- Wall-mounted Planters: For a unique and space-saving display, consider mounting your Boston fern in a wall-mounted planter. This can create a living wall effect and bring life to an otherwise empty wall.
- Table Centerpiece: Place your Boston fern in a decorative container and use it as a table centerpiece. This can add a touch of elegance and natural beauty to your dining or coffee table.
- Porch or Patio: If you have an outdoor space, consider displaying your Boston fern on your porch or patio. Pair it with other shade-loving plants or colorful flowers for a visually appealing arrangement.
Remember to provide your Boston fern with the appropriate light, humidity, and watering conditions, regardless of the display method you choose. With proper care and a creative display, your Boston fern can be a stunning addition to your indoor or outdoor space.
👍 Pro Tips for Healthy Growth
To ensure your Boston fern thrives indoors, follow these expert tips for optimal growth and health:
- Choose an indoor location with indirect sunlight: Boston ferns prefer bright, indirect light, such as an east-facing window. Avoid direct sunlight, as it can scorch the fronds.
- Maintain high humidity levels: Boston ferns thrive in high humidity. Mist your fern daily, place it in a light-filled bathroom or kitchen, or set the pot on a tray of pebbles filled with water to increase humidity.
- Prune and remove browning leaves: Regularly trim away any browning or dead leaves to encourage new growth and maintain a healthy appearance.
- Water ferns carefully and avoid overwatering: Keep the soil consistently moist, but avoid overwatering, as this can lead to root rot. Check the soil daily and water when it feels dry.
- Fertilize ferns regularly: Feed your Boston fern with a balanced houseplant fertilizer during the growing season, following the directions on the product. This will provide the necessary nutrients for healthy growth.
By following these pro tips, you can create the ideal environment for your Boston fern to grow and thrive indoors. With proper care and attention, your fern will reward you with lush, vibrant foliage.
❓ FAQ
How often should I water my Boston fern?
Water your Boston fern when the top inch of the soil feels dry. This may vary depending on the humidity and temperature in your home, but generally, you should check the soil daily and water as needed to keep it consistently moist.
Can Boston ferns grow in low light?
Boston ferns prefer bright, indirect light, such as an east-facing window. They can tolerate lower light conditions, but their growth may be slower and their fronds less vibrant.
How do I increase humidity for my Boston fern?
To increase humidity for your Boston fern, you can mist the plant daily, place it in a light-filled bathroom or kitchen, or set the pot on a tray of pebbles filled with water, ensuring the pot does not touch the water.
How do I propagate a Boston fern?
To propagate a Boston fern, divide the plant during repotting. Carefully separate the root ball into smaller sections, each with healthy roots and fronds. Plant each division in a new pot with fresh soil, and provide proper care to encourage new growth.
Are Boston ferns toxic to pets?
Boston ferns are non-toxic to both cats and dogs, making them a safe choice for households with pets.
How do I prevent root rot in my Boston fern?
To prevent root rot, avoid overwatering your Boston fern and ensure the soil drains well. Allow the soil to dry out slightly between waterings, and maintain good air circulation around the plant.
How often should I fertilize my Boston fern?
Fertilize your Boston fern with a balanced houseplant fertilizer during the growing season (spring and summer), following the directions on the product.
📝 Final Thoughts
In conclusion, Boston ferns are a classic and popular houseplant choice thanks to their graceful, arching fronds and lush green foliage. While they require a bit more care than some houseplants, Boston ferns are well worth the effort for the tropical look they bring indoors.
By providing the proper growing conditions including indirect light, high humidity, warm temperatures, and consistent moisture, Boston ferns can thrive indoors for many years. Avoid common problems like pests, diseases, and watering issues by following the care tips provided. Experiment with different decorative displays to highlight the beauty of this plant.
With the proper care outlined in this complete indoor growing guide, you can keep your Boston fern looking healthy, vibrant, and beautiful. This graceful plant can bring a touch of the tropics and a breath of fresh air to any indoor space. Follow the tips provided on lighting, watering, humidity, fertilizing, troubleshooting problems, and more to help ensure your Boston fern reaches its full potential.
If you love the look of arching green fronds, the Boston fern is sure to be a stunning addition to your home. With a little attention to its preferences, this classic fern can provide you with years of natural beauty.
📚 Further Reading
📗 Learn More about Boston Fern
📃 Boston Fern Varieties and Cultivars
📚 References
