The Giant Sword Fern (Nephrolepis biserrata) is a large, tropical fern native to Florida, Mexico, the West Indies, Central America, South America, Africa, and southeast Asia. It is also known as the broad sword fern or macho fern. This impressive plant can grow quite tall, with arching fronds reaching 3-8 feet long.
👀 Overview
Some key facts about N. biserrata include:
- Native habitat is tropical areas worldwide
- Grows best in moist, shaded locations
- Fronds can reach up to 8 meters long, making it the largest sword fern species
- Often grown as a houseplant or in outdoor containers
Physical Description
N. biserrata is an evergreen, erect fern that forms large mounds of arching fronds.
- Fronds are long and narrow, ranging from 1-2.5 meters long.
- Pinnae (leaflets) are up to 23 cm long and 2 cm wide.
- Stipes (stems) are 10-50 cm long and 4 mm wide.
- The rachis (central stalk) is light brown and sparsely to moderately covered in reddish-brown, hair-like scales.
The fronds are a bright green color with pointed tips. The leaf margins are finely double-toothed and densely pubescent (hairy) on the underside.
Growth Requirements
N. biserrata thrives in the following conditions:
- Light: Grows best in partial to full shade. Avoid direct sunlight.
- Soil: Moist, well-drained soil. Prefers loam, clay, or sand.
- pH: Does well in acidic to neutral soil pH.
- Water: Keep soil consistently moist but not saturated.
Uses in Cultivation
N. biserrata is valued in cultivation for its large, showy fronds. It can be used:
- In shady garden beds and borders
- As a groundcover in woodland gardens
- In large containers on patios and porches
- As a houseplant in indoor spaces with bright, indirect light
There is a popular cultivar called ‘Macho’ selected for its very large fronds.
| 📖 Common name | Giant Sword Fern, Macho Fern |
| 🔬 Botanical name | Nephrolepis biserrata |
| 🫴 Care Difficulty level | Moderate |
| ☠️ Toxicity | Non-toxic to pets and humans |
| 💨 Air-purifying Qualities | Moderate |
| 🌱 Soil Type and pH | Well-draining, slightly acidic to neutral |
| ☀️ Sun Exposure | Partial shade to full shade |
| 🍪 Edibility | Not edible |
| 🌴 Plant type | Fern |
| 🍃 Foliage Type | Evergreen |
| 🌿 Color of leaves | Bright green |
| 🌸 Flower color | N/A |
| 💥 Bloom time | N/A |
| 🚀 Growth Speed | Moderate to Fast |
| 📏 Mature Size | Up to 4-6 feet |
| 🔄 Life Cycle | Perennial |
| 🌍 Hardiness zones | 9-11 |
| 🗺️ Native area | Tropical and subtropical regions, particularly Central and South America |
💚 Giant Sword Fern Care
Caring for the Giant Sword Fern is relatively straightforward. Stick to its preferences for warm, humid conditions and bright filtered light. Water frequently to keep the soil consistently moist but not soggy. Repot every few years in a rich, well-draining mix. With the proper care, this impressive tropical fern will thrive indoors or out.
☀️ Light ☀️
The Giant Sword Fern thrives in bright, filtered light. Direct sun should be avoided, especially hot afternoon sun which can scorch the fronds.
Ideal Light Conditions
- Bright indirect sunlight for 4-6 hours per day
- East or west-facing windows work well
- Sheer curtains can filter direct morning or evening sun
- Avoid direct southern exposure
Light Levels
- Ideal light levels are 2,000-4,000 lux or 200-400 FC.
- Minimum light levels should be above 1,000 lux (100 FC).
- Use a light meter app to measure light in the planned location.
Low Light Symptoms
Insufficient light will cause:
- Slow growth
- Smaller fronds
- Foliage yellowing or browning
- Fronds thinning out
Supplemental Lighting
- LED grow lights can provide extra light if sunlight is inadequate.
- Position lights 12-18 inches above the fern.
- Provide 12-16 hours of supplemental light daily.
Light Acclimation
- Acclimate new plants to increase light levels gradually.
- Rotate the plant periodically for even light exposure.
Seasonal Light
- Provide maximum light in spring through fall.
- Reduce intensity slightly in winter months.
Monitor light levels and adjust as needed to keep the Giant Sword Fern healthy and actively growing. Filter direct sun to prevent leaf burn. Supplement with grow lights if sunlight is low.
💧 Water
The Giant Sword Fern thrives in moist soil and requires frequent watering. Allow the top inch or two of soil to dry out between waterings.
Watering Frequency
- Indoors: Water 1-2 times per week.
- Outdoors: Water 2-3 times per week during warm months if rainfall is insufficient.
Watering Method
- Water thoroughly until water drains from the drainage holes at the bottom of the pot.
- Avoid letting the plant sit in water. Empty any water that collects in the saucer.
- Use room temperature water, not cold water directly from the tap.
Water Needs
- Prefers consistently moist soil. Do not let the soil completely dry out.
- Can tolerate occasional drying of the soil but should not remain dry for long periods.
- Requires higher watering frequency in warmer temperatures and lower humidity environments.
Overwatering
- Signs of overwatering include yellow fronds, root rot, and soggy soil.
- Allow the soil to partially dry between waterings.
Underwatering
- Signs of underwatering include brown crispy fronds and dry soil.
- Increase watering frequency if this occurs.
Humidity
- Thrives in average home humidity of 40-50%.
- Occasional misting can boost humidity around the fronds.
Soil
- Use a well-draining potting mix. Avoid heavy, dense soil.
- Add peat moss or orchid bark to improve drainage and aeration.
Monitor soil moisture and adjust watering as needed. Keep the Giant Sword Fern consistently moist without oversaturating for healthy growth.
🪴 Soil
The Giant Sword Fern thrives in a rich, well-draining potting mix. The ideal soil provides moisture retention while allowing excess water to drain away easily.
Soil Requirements:
- Well-draining – The soil must drain freely to prevent soggy conditions. Add perlite, pumice, or horticultural charcoal to improve drainage.
- Moisture-retentive – Retains some moisture but does not stay wet or saturated. Incorporate peat moss or coco coir.
- Nutrient-rich – The soil should contain organic matter for nutrients. Compost, worm castings, or composted manure provide nutrients.
- Acidic pH – Between 5.5 and 6.5 pH is ideal. Ferns prefer acidic conditions.
- Aerated – The soil needs air pockets for the roots. Perlite and orchid bark provide aeration.
Recommended Soil Mix:
- 40% peat moss or coco coir for moisture retention
- 20% perlite, pumice, or charcoal for drainage
- 20% compost, worm castings, or composted manure for nutrients
- 20% potting soil for structure
You can also use a pre-mixed indoor potting mix with added perlite or orchid bark for aeration and drainage. Avoid dense, heavy potting mixes that stay soggy. Re-pot annually in fresh soil.
Outdoors:
- Amend native soil with compost and organic material to create a rich planting bed.
Provide the Giant Sword Fern with a well-aerated, moist, acidic soil to encourage lush, healthy frond growth. Ensure the soil drains freely to prevent root rot issues.
🍼 Fertilizer
The Giant Sword Fern benefits from occasional fertilization during the active growing season to maintain vibrant foliage.
When to Fertilize
- Early spring through summer
- Avoid fertilizing in fall and winter when growth slows
Frequency
- Every 4-6 weeks during the growing season
- Reduce frequency in low light conditions
Type of Fertilizer
- Balanced liquid fertilizer (20-20-20)
- Orchid fertilizer, fish emulsion, or seaweed extract
- Look for ferns or foliage plants on the label
Application:
- Dilute liquid fertilizers to half strength
- Foliar feed by spraying diluted fertilizer on the fronds
- Apply as a soil drench around the base of the plant
Signs of Deficiency:
- Pale or yellowing fronds
- Smaller than normal new growth
- Overall lackluster appearance
Over-Fertilization:
- Leaf tip burn
- Root damage
- Salt buildup in soil
With proper care, fertilization may not be needed. Repot in fresh soil annually to replenish nutrients. Avoid over-fertilizing the Giant Sword Fern and only use half strength applications.
🌡️ Temperature
The Giant Sword Fern thrives in warm temperatures between 60-80°F (15-27°C). Avoid exposing it to cold drafts or temperatures below 50°F (10°C).
Ideal Temperature Range:
- Daytime Temps: 65-75°F (18-24°C)
- Nighttime Temps: 60-70°F (15-21°C)
Outdoor Hardiness:
- USDA Zones 10-11
- Can be grown outdoors year-round in frost-free climates
Indoors:
- Keep away from cold drafts from windows or doors
- Avoid rooms with large temperature fluctuations
- Use a space heater to maintain warm temps in winter
Cool Temperatures:
- Below 50°F (10°C) can cause leaf damage
- Growth will slow down dramatically below 60°F (15°C)
High Temperatures:
- Can tolerate temps up to 85°F (29°C)
- Provide good air circulation and humidity at high temps
Monitor for Temperature Stress:
- Wilting, drooping fronds indicate too cold
- Crispy, dried out fronds indicate too hot
Maintain indoor temperatures between 60-80°F year-round. Protect from cold drafts in winter. The Giant Sword Fern thrives in warm, tropical conditions. Monitor for signs of temperature stress and adjust as needed.
💦 Humidity
The Giant Sword Fern thrives in humid conditions. Replicate its native tropical habitat by providing average to high humidity around this plant.
Ideal Humidity Levels:
- Minimum of 40% relative humidity
- Prefers consistent 60-80% humidity
- Can tolerate up to 100% humidity
Increasing Humidity:
- Use a humidifier near the plant to raise humidity levels
- Set humidifier to maintain 60-80% humidity
- Use a pebble tray filled with water
- Mist the plant daily using a spray bottle
- Grow in a bathroom or kitchen where humidity tends to be higher
Signs of Low Humidity:
- Brown, crispy leaf edges
- Fronds drying out
- Slow growth
Signs of High Humidity:
- Fungal leaf spots
- Rotting stems
- Mold growth on soil
Outdoors:
- Plant in shaded areas away from direct sun
- Provide ample water to the soil
- Mist fronds frequently
Monitor humidity around the Giant Sword Fern. Increase levels if needed to prevent dried out fronds. Avoid excessively wet conditions that can lead to fungal issues.
📃 Types of Giant Sword Fern
There are no well-defined cultivars or varieties of the Giant Sword Fern that are commonly grown.
🪴 Potting and Repotting Giant Sword Fern
The Giant Sword Fern thrives when slightly rootbound, so repotting is only needed every 2-3 years as the plant grows.
Choosing a Pot:
- Select a pot 2-4 inches wider than the current root ball.
- Make sure the pot has drainage holes to prevent soggy soil.
- Heavy plastic or glazed ceramic pots help retain moisture.
Soil Mix:
- Use a rich, well-draining potting mix amended with perlite, orchid bark, or charcoal.
- Soil should be moist but not soggy.
Repotting Steps:
- Repot in early spring before growth resumes.
- Carefully remove from current pot and loosen any circled roots.
- Prune off any dead roots or fronds.
- Place in new pot at the same soil depth as before.
- Fill gaps around root ball with fresh potting mix.
- Water thoroughly after repotting.
Propagating when Repotting:
- The rhizomes can be divided to propagate new plants.
- Ensure each division has 3-5 fronds and healthy roots.
- Repot divisions in small pots using a well-draining mix.
Avoid disturbing the Giant Sword Fern’s roots often. Repot every 2-3 years in spring before active growth starts. Divide rhizomes at repotting for propagation.
✂️ Pruning Giant Sword Fern
Regular pruning of old, damaged, or dead fronds will help maintain an attractive appearance and encourage new growth.
When to Prune:
- Early spring as new fronds emerge
- Remove any fronds that yellow or brown during the year
Tools:
- Use clean, sharp scissors or pruning shears
- Sterilize tools between plants to prevent disease spread
How to Prune:
- Cut fronds at the base, where they emerge from the soil
- Avoid leaving stubs – make clean cuts
- Remove only damaged or dead fronds, not healthy green ones
Pruning Tips:
- Prune off any dried tips or edges on fronds
- Cut away fronds that are mostly yellowed or browned
- Remove fallen or broken fronds
Overgrown Plants:
- Can be cut back by 1/3 to 1/2 to reduce size
- New flush of growth will emerge after pruning
Propagating when Pruning:
- Healthy fronds removed during pruning can be used for propagation
- See the Propagation section for details
Regular pruning improves appearance and air circulation. Remove any dead, diseased, or unsightly fronds. Sterilize tools between plants.
🌱 How to Propagate Giant Sword Fern
The Giant Sword Fern can be easily propagated by dividing the rhizomes or using frond cuttings. Spores can also be collected and grown into new plants.
Rhizome Division
- Divide congested root balls when repotting in spring.
- Ensure each division has 3-5 fronds and plenty of healthy roots.
- Use a clean knife or shears to separate rhizome sections.
- Plant divisions in small pots using well-draining potting mix.
- Keep divisions humid, warm, and in bright indirect light as they establish.
- Water sparingly until new growth emerges after 1-2 months.
Frond Cuttings
- Take 4-6 inch cuttings from healthy fronds.
- Remove lower leaves and stick into moist potting mix.
- Ideal mix is half peat and half perlite or vermiculite.
- Keep warm (70-75°F) and humid with bright, indirect light.
- Root initials will form after 1-2 months. Pot up individually.
Spores
- Spores appear as brown dots on the undersides of mature fronds.
- Use a paper envelope to collect fallen spores.
- Sow spores thickly on the soil surface of seed trays.
- Cover trays with plastic to retain humidity and place in bright indirect light.
- Thin and transplant sporlings once they reach 2-3 inches tall.
Take advantage of the Giant Sword Fern’s easy propagation abilities. Dividing rhizomes is simplest, but frond cuttings and spores also work well. Maintain warm, humid conditions for best results.
🐛 Common Pests
Giant Sword Fern is generally not susceptible to serious pest issues when provided proper care. However, some potential pests to monitor for include:
Mealybugs
- Appear as small white cottony masses on leaves and stems
- Can cause yellowing, stunting, and leaf drop
- Wipe off with cotton swabs dipped in alcohol or use insecticidal soap
Scale Insects
- Form hard brown or white lumps on leaves and stems
- Can stunt growth and damage foliage
- Prune affected parts and use horticultural oil or insecticidal soap treatment
Spider Mites
- Tiny red or black dots on undersides of leaves
- Cause stippling, discoloration, and leaf drop
- Knock off with water spray or use insecticidal soap/neem oil
Aphids
- Green, yellow, black soft-bodied insects on new growth
- Can distort and curl leaves
- Use strong water spray or insecticidal soap treatment
Snails/Slugs
- Chew irregular holes in fronds overnight
- Hand pick or use iron phosphate bait
Isolate new plants and inspect regularly for signs of pests. Remove affected parts immediately and treat using gentle, organic pest control methods to prevent spreading. Maintain plant health through proper care.
🩺 Common Problems With Giant Sword Fern
Leaf browning or yellowing
- Causes: Too much sun, underwatering, or low humidity
- Solutions: Move to shadier location, increase watering frequency, use pebble tray or humidifier
Leaf drop
- Causes: Overwatering, underwatering, or cold drafts
- Solutions: Adjust watering practices, move plant away from drafty areas
Slow growth
- Causes: Insufficient light, low temperatures, or lack of nutrients
- Solutions: Provide brighter indirect light, maintain warm temps, fertilize monthly in growing season
Root rot
- Causes: Overwatering or slow draining soil
- Solutions: Allow soil to partially dry between waterings, repot in better draining soil mix
Pests like mealybugs, mites, or scale
- Solutions: Isolate and treat with horticultural oils or insecticidal soaps, improve plant health
Fungal leaf spots
- Causes: Excess moisture or high humidity
- Solutions: Improve air circulation, water early in day so leaves dry out
Crispy frond tips
- Causes: Dry air, fertilizer burn, or tap water
- Solutions: Increase humidity, reduce fertilizer, use distilled or rain water
Monitor plants closely and address any issues promptly. Maintaining proper growing conditions and plant health is key to preventing problems. Sterilize tools and isolate affected plants to prevent spreading.
🖼️ Display Ideas
With its imposing arching fronds, the Giant Sword Fern makes a dramatic statement in any setting. Take advantage of its tropical look by using these display ideas:
Indoors:
- Place in an entryway or corner to create an inviting jungle feel
- Let it trail from a mantle or bookshelf to add organic texture
- Pair with other tropicals like Monstera, Philodendron, or Ficus
- Use as a room divider or privacy screen
- Add uplights or spotlights to showcase the fronds
Outdoors:
- Plant in groups of 3-5 for high visual impact
- Use as a living screen or hedge for privacy
- Border a shade garden or walkway
- Place in a courtyard or atrium for an exotic feel
- Let it grow up trees or stone walls for a natural look
- Underplant with shade-loving caladiums, begonias, or impatiens
Containers:
- Choose a heavy pot that won’t blow over in wind
- Use a tall cylinder pot to show off upright fronds
- Plant in baskets or hanging planters
- Combine with other ferns like autumn fern or holly fern
Take advantage of this fern’s huge size and lush tropical foliage. Display it prominently indoors or out to create an exotic, artsy look in your spaces.
👍 Pro Tips for Healthy Growth
Lighting
- Rotate the plant periodically so all sides get adequate light exposure. This prevents one-sided growth.
- Wipe dust off fronds periodically to maximize light absorption.
Watering
- Allow water to fully permeate the root ball, not just the top inch of soil. Proper saturation encourages growth.
- Water with room temperature or lukewarm water. Cold water straight from the tap can shock the roots.
Humidity
- Group plants together to benefit from their collective transpiration. More plants release more moisture into the air.
- Use pebble trays with larger rocks that retain more water. Replenish water frequently to keep evaporation high.
Fertilizing
- Incorporate slow release fertilizer granules into the potting mix before repotting. This provides nutrients over time.
- Foliar feed by spraying diluted liquid fertilizer directly on the fronds. The leaves will absorb nutrients efficiently.
Pruning
- Sterilize pruning shears in between cuts to prevent transferring diseases. Dip shears in rubbing alcohol or diluted bleach solution.
- Prune off any fronds that emerge directly from the soil, as these will not grow to full size.
Troubleshooting
- Look for pest or disease problems early. Isolate affected plants to prevent spreading.
- Identify and address issues promptly to maintain optimal plant health and growth.
Follow these tips to keep your Giant Sword Fern thriving happily in your indoor or outdoor spaces! Let me know if you need any clarification or have additional questions.
❓ FAQ
How much light does a Giant Sword Fern need?
The Giant Sword Fern thrives in bright, indirect sunlight. Provide 3-6 hours of filtered sunlight per day. Avoid hot, direct midday sun which can scorch the fronds.
What temperature range is best?
Ideal temperatures are 60-80°F (15-27°C). Avoid cold drafts below 50°F (10°C) which can damage leaves. Provide warmth in winter.
How often should I water this fern?
Water 1-2 times per week, allowing the top inch of soil to dry out between waterings. Increase frequency in warmer months. Take care not to oversaturate the soil.
Should I mist my Giant Sword Fern?
Occasional misting can help increase humidity around the fronds. But be careful not to create excess moisture leading to fungal issues.
What type of potting mix does this plant need?
Use a rich, well-draining potting mix. Incorporate peat moss for moisture retention and perlite/orchid bark for aeration.
When should I repot my Giant Sword Fern?
Repot every 2-3 years in the spring. Choose a pot just 2-4 inches larger than the current container. Divide congested rhizomes at repotting.
How do I propagate new Giant Sword Fern plants?
Propagate by dividing rhizomes or taking frond cuttings. You can also collect and sow spores. See the Propagation section for details.
Why are my fern’s fronds turning brown or yellow?
This is usually caused by too much sun, underwatering, low humidity, or cold drafts. Adjust its care to resolve the issue.
📝 Final Thoughts
With its imposing size and tropical appeal, Giant Sword Fern makes a striking addition to gardens and homes. While it has simple care needs, following the guidance in this care guide will ensure your fern thrives.
Providing the right amounts of bright, indirect light, warm temperatures, and consistent humidity are key to keeping this plant happy. Allow the soil to dry out slightly between waterings and fertilize occasionally during the growing season.
Repot every few years in a well-draining mix amended with peat moss or orchid bark. Prune away any dead or damaged fronds to maintain an attractive appearance. Propagate new plants easily by dividing the rhizomes.
Address any pest or disease issues promptly and maintain proper growing conditions to prevent problems. With the proper care outlined here, your Giant Sword Fern will grow into an imposing, healthy specimen.
We hope you’ve found this guide helpful! Let us know if you have any other questions – we’re always happy to help out fellow plant lovers. Happy growing!
📚 Further Reading
📗 Read more info on Giant Sword Fern
📚 References
📘 Nephrolepis biserrata Plant Directory – University of Florida IFAS Center for Aquatic and Invasive Plants.
📘 Nephrolepis biserrata Plant Profile – North Carolina State University.
