Boston Ferns (Nephrolepis exaltata) are elegant plants with long, slender leaves that cascade over the sides of their pot. You can grow a Boston Fern indoors in all climates or outdoors in a warm, frost-protected, and shaded spot.
Boston Ferns prefer a moist but not soggy soil, and they like a humid environment. You can mist the leaves regularly, group them with other plants, or use a humidifier to give them the conditions they prefer.
Plant Boston Ferns in hanging baskets or position them high on a shelf so their dramatic, cascading foliage is on full show.
Where to Plant Boston Fern
Growing Boston Ferns in Hardiness Zones 9 to 11 Watering: These ferns love moisture and require regular watering to keep the soil consistently moist but not waterlogged. They are not drought-tolerant, so during dry spells or hot weather, you’ll need to water them more frequently. Light: They prefer bright, indirect light, making in full or partial shade ideal. Direct sunlight can scorch their delicate fronds, so dappled shade or filtered light is best. Wind Protection: Boston ferns are sensitive to drying winds, which can cause their fronds to dry out and turn brown. A sheltered location, like a covered patio or an area protected by other plants, works well.
Growing Boston Ferns Outside of Zones 9 to 11 Container Growing: In colder zones, Boston ferns are often grown as container plants that can be moved indoors when temperatures drop below 45°F (7°C). This flexibility allows them to avoid frost damage and continue thriving indoors. Indoor Care: When kept indoors, Boston ferns require high humidity and indirect light. You can mist them regularly or place a humidifier nearby to maintain humidity. They should be kept away from drafts and heating vents, which can dry them out.
Soil and fertilizer:
Use a well-draining potting mix rich in organic matter, and fertilize the fern with a balanced liquid fertilizer diluted to half-strength every 4-6 weeks during the growing season (spring and summer).
Fertilize Boston Ferns fortnightly in spring and summer with an indoor plant fertilizer to encourage new growth. Use Scotts Osmocote Pour Feed for Indoor Plants—this is a simple to use’measure and pour’ feed that contains the right balance of nutrients. If you’d prefer a longer-term fertilizing product with fewer applications, apply Scotts Osmocote Controlled Release Fertilizer for Indoor Plants in early spring and again in early autumn; this product feeds for up to 6 months.
Fertilize in ground-planted Boston Ferns with Scotts Osmocote Controlled Release Fertilizer: All Purpose in spring and again in early autumn.
In the warmer months of spring and summer, Boston Fern will appreciate more regular watering and a higher humidity. To increase the humidity around Boston Ferns, group them with other plants to create a microclimate or mist them with a spray bottle regularly. You can also sit their pot on a saucer filled with pebbles and water; as the water evaporates, it will humidify the air.
Remove any dead or damaged fronds at the base to promote new growth. To remove the dust that collects on Boston Fern leaves, pop it into the shower, bring it outside for a gentle hose off, or use a soft, damp cloth to gently remove stubborn dust.
Pests & Diseases
Boston ferns are susceptible to several pests and problems, both indoors and outdoors. Pests Affecting Boston Ferns. Mealybugs: Identification: small, white, cotton-like insects that cluster on leaves and stems. Control: Wipe affected areas with a cotton swab dipped in rubbing alcohol, or use insecticidal soap. Repeat treatments as necessary. Spider Mites: Identification: Tiny, spider-like pests that cause fine webbing and speckled yellow or brown leaves. Control: Increase humidity by misting or placing a humidity tray nearby. Wash the leaves with water or use insecticidal soap. Neem oil can also be effective. Whiteflies: Identification: small, white-winged insects that fly up in a cloud when the plant is disturbed. Control: Use yellow sticky traps to catch adults. Spray with insecticidal soap or Neem oil to control nymphs and adults. Snails, Slugs, and Caterpillars: Identification: holes or ragged edges on fronds, slime trails (for snails and slugs). Control: Handpick and remove them at dusk or dawn. For severe infestations, use organic snail and slug bait.
Diseases Affecting Boston Ferns. Blight Fungus: symptoms: dark brown spots on the foliage, crown, and roots. Cause: This fungus lives in the soil and can be spread by splashing water. Control: For potted ferns, remove the plant from its container, discard the old soil, and repot in a sterilized pot with fresh potting mix. For outdoor ferns, improve air circulation and avoid overhead watering. If the problem persists, consider applying a fungicide labeled for blight. Root Rot: Symptoms: Wilting, yellowing leaves, and black, mushy roots. Cause: Overwatering or poorly draining soil leads to excess moisture, allowing fungi to thrive. Control: Potted Ferns: Remove the plant from its pot, trim away diseased roots, and repot in a sterile container with fresh, well-draining potting mix. Discard the old soil. Outdoor Ferns: Amend the soil with organic matter (like compost or sand) to improve drainage. Divide the plant, removing the diseased sections, and replant the healthy portions in a different location with better drainage.
Preventive Measures. Regular Monitoring: Check your plants regularly for signs of pests and diseases to catch problems early. Proper Watering: Water consistently, but allow the top inch of soil to dry out slightly between waterings to prevent root rot. Good Air Circulation: Space plants to ensure adequate air circulation, which helps reduce the risk of fungal diseases. Sterilize Tools and Pots: Use clean, sterilized tools and pots to prevent the spread of diseases. Natural Predators: Encourage beneficial insects, like ladybugs and predatory mites, that help control pest populations naturally.
