How to Grow Fishbone Fern
iNaturalist
Fishbone Fern
Nephrolepis obliterata
herbThe Fishbone Fern is a tropical evergreen fern characterized by its distinctive arching fronds with small, densely-packed pinnae that resemble fish bones. It is a compact, slow-growing variety of the Boston Fern family, making it ideal for indoor container cultivation. This fern thrives in humid environments and is prized for its ornamental foliage and air-purifying qualities.
When should you plant Fishbone Fern in your zone?
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Example Fishbone Fern timeline · Pittsburgh, PA (Zone 6b)
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Plant Fishbone Fern
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Fishbone Fern
Late summer into fallBefore the first fall frost (≈ Nov 8)
Sample dates for Pittsburgh, PA. Sign up to get exact Fishbone Fern dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 10b-11 outdoors; commonly grown indoors in cooler climates
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Establishment
2-4 weeksYoung fern with emerging fronds, typically 2-4 inches tall when acquired as a starter plant
Maintain high humidity (50-60%), consistent moisture, and indirect light. Avoid fertilizing for first month. Keep away from cold drafts and heat vents.
Vegetative Growth
3-6 monthsFronds gradually unfurl and lengthen, displaying the characteristic fishbone pattern of pinnae
Continue misting 2-3 times weekly. Feed with diluted balanced liquid fertilizer every 3-4 weeks during growing season (spring/summer). Rotate plant weekly for even growth.
Mature Fronds
Ongoing in proper conditionsFully developed arching fronds with dense, symmetrical pinnae arrangement reaching 12-18 inches
Maintain consistent care routine. Remove any brown or yellowing fronds at the base. Humidity remains critical; use humidifier if indoor air is dry.
Spore Production
Occurs naturally on mature frondsSmall brown sori (spore clusters) may appear on undersides of mature fronds
This is normal and healthy. Spores can be collected for propagation if desired, though vegetative propagation via runners is easier.
Decline/Rejuvenation
As neededOld fronds may yellow or become sparse; plant may need pruning
Cut back yellowed fronds. Repot into fresh soil every 12-18 months to refresh. Increase humidity and maintain consistent watering.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Increase humidity to 60%+; mist fronds regularly. Spray with neem oil or insecticidal soap if infestation occurs. Isolate affected plant.
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Remove with damp cloth or cotton swab dipped in rubbing alcohol. Treat with neem oil spray weekly for 3 weeks if severe.
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Allow top inch of soil to dry between waterings. Use yellow sticky traps. Apply sand mulch on soil surface. Use neem oil if population grows.
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Remove manually with cloth or brush. Treat with horticultural oil or neem oil spray; repeat every 7-10 days.
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Increase humidity. Spray with insecticidal soap or neem oil. Remove heavily infested fronds.
Uses
Air Purification
HouseholdFishbone Ferns are recognized by NASA for their ability to remove formaldehyde and xylene from indoor air, helping improve home air quality. They actively absorb toxins through their fronds, making them excellent additions to bedrooms or living spaces. [source]
Interior Decoration & Landscaping
CraftThe graceful arching fronds with their distinctive fishbone pattern make this fern a striking ornamental specimen for tabletops, shelves, hanging baskets, and shaded garden corners. Its compact form and soft texture add tropical ambiance to both modern and traditional décor. [source]
Traditional Herbal Medicine
MedicinalRelated Nephrolepis species have been used in traditional Asian medicine for their potential anti-inflammatory and antimicrobial properties. While modern research is limited, the plant has historical use in herbal preparations. [source]
Humidity & Microhabitat Creation
WildlifeThe dense fronds and moisture-loving nature of Fishbone Ferns create humid microclimates ideal for supporting beneficial insects, small reptiles, and other humidity-loving creatures in indoor garden setups or conservatories. [source]
Humidity Regulation
HouseholdThrough transpiration, Fishbone Ferns naturally release moisture into the air, helping increase ambient humidity levels in indoor spaces. This dual benefit of decoration and humidification makes them valuable for dry climates or winter heating scenarios. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Not harvested in traditional sense. Remove dead or yellowing fronds by cutting at the base with clean scissors. Prune to maintain shape and encourage bushier growth. Can propagate by dividing clumps or collecting spores from mature sori.
Fun Facts
- 🌱 Fishbone Ferns are called 'Nephrolepis obliterata' because the smaller pinnae (leaflets) partially overlap or 'obliterate' the midrib, creating their characteristic dense, fine-textured appearance unlike the more open Boston Fern.
- 🌱 This fern can propagate through runners with baby plantlets that develop on stolons, allowing easy propagation—simply pin runners to moist soil or water until roots form, then separate.
- 🌱 Ferns have existed for over 360 million years, predating flowering plants and dinosaurs. Fishbone Ferns are living descendants of these ancient plants that once dominated Earth's forests.
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