Gunnera vs New Zealand Flax Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Gunnera

Gunnera

Gunnera manicata

VS
New Zealand Flax

New Zealand Flax

Phormium tenax

Gunnera

Gunnera

Gunnera manicata

Gunnera manicata, commonly known as Giant Rhubarb, is a massive, rhizomatous perennial plant prized for its enormous, textured leaves. Native to South America, it is primarily an outdoor plant, grown for its dramatic architectural presence in gardens and near water features. The leaves can reach impressive sizes, up to 2.5 meters across, creating a bold statement. While admired for its striking appearance, it is not suitable for indoor cultivation due to its size and specific environmental needs. It produces cone-shaped inflorescences of small reddish-green flowers in the summer.

Gunneraceae Southern Brazil, Colombia
✨ Features: Dramatic foliage, architectural presence
📖 Read Complete Gunnera Guide
New Zealand Flax

New Zealand Flax

Phormium tenax

Phormium tenax, commonly known as New Zealand Flax, is a large, evergreen perennial plant forming clumps of long, strap-like leaves. It's native to New Zealand and is primarily an outdoor plant, valued for its dramatic architectural form and fiber production. The leaves can grow up to 3 meters long and come in various colors, from green to bronze and variegated forms. While it can be grown indoors, it requires very bright light and significant space, making it challenging for most homes. People grow it for its striking appearance in gardens and landscapes.

Asphodelaceae New Zealand
✨ Features: Dramatic architectural form, fiber production (traditionally used by Maori people)
📖 Read Complete New Zealand Flax Guide

Quick Plant Comparison

Feature Gunnera New Zealand Flax
Light Full sun to partial shade Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily.
Watering 2-3 times per week, depending on weather conditions Every 1-2 weeks, depending on light and temperature. Less frequent in winter.
Humidity 60-80% 30-50%
Temperature 10-25°C 10-27°C
Care Level Expert Expert
Growth Rate Fast Moderate
Max Height Not applicable for indoor growing. Outdoors: 2-3 meters 1-2 meters indoors (much larger outdoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Rich, moisture-retentive soil with good drainage Well-draining soil is crucial. A mix of potting soil, sand, and perlite is suitable.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes weekly during the growing season 30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Gunnera

Scientific Name Gunnera manicata
Family Gunneraceae
Native To Southern Brazil, Colombia
Also Known As Giant Rhubarb, Dinosaur Food
Leaves The leaves of Gunnera manicata are palmate, deeply lobed, and heavily textured with prominent veins. They are typically dark green and can reach up to 2.5 meters in diameter. The leaf stalks are thick and prickly.
Flowers Gunnera manicata produces cone-shaped inflorescences of small reddish-green flowers in the summer. The flowers are not particularly showy but add to the plant's overall architectural interest. It rarely flowers indoors.

New Zealand Flax

Scientific Name Phormium tenax
Family Asphodelaceae
Native To New Zealand
Also Known As New Zealand Flax, Harakeke
Leaves Long, strap-like leaves that can grow up to 3 meters long. The leaves are stiff and leathery, with a smooth texture. Colors range from green to bronze, red, and variegated forms.
Flowers Rarely flowers indoors. Outdoors, it produces tall flower stalks with reddish-brown flowers in summer.

📏 Size & Growth — Plant Comparison

Gunnera

Height Not applicable for indoor growing. Outdoors: 2-3 meters
Spread Spreads via rhizomes, can reach 4-5 meters wide
Growth Rate Fast
Growth Pattern Gunnera manicata grows from a large, rhizomatous base. It produces enormous leaves that unfurl from the center of the plant, creating a dense and spreading canopy. It is a vigorous grower and can quickly fill a large space.

New Zealand Flax

Height 1-2 meters indoors (much larger outdoors)
Spread 1-1.5 meters indoors (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern Forms a dense clump of upright, arching leaves. Spreads via rhizomes, potentially becoming quite large over time.

🌱 Propagation — Comparing Plant Growth

Gunnera

Methods: Division, Seed

Difficulty: Moderate

Tips: Divide rhizomes in early spring or late fall. Sow seeds in spring after a period of cold stratification.

New Zealand Flax

Methods: Division, Seed

Difficulty: Moderate

Tips: Division is best done in spring. Carefully separate the rhizomes and plant them in well-draining soil. Seeds can be sown in spring after soaking them in water for 24 hours.

✨ Benefits & Features — Comparing Plant Value

Gunnera

Gunnera manicata is unique due to its massive size and dramatic foliage, making it a standout architectural plant. Its leaves are among the largest of any herbaceous plant, creating a prehistoric and tropical aesthetic.

  • ✓ Adds a dramatic, architectural element to the garden.
  • ✓ Provides a focal point and visual interest.
  • ✓ Creates a lush, tropical atmosphere.
  • ✓ Attracts beneficial insects and pollinators.
  • ✓ Can be used to create shade and shelter for other plants.
  • ⚠️ Toxic to pets

New Zealand Flax

New Zealand Flax is known for its long, strap-like leaves and dramatic architectural form. It is a versatile plant that can be used in a variety of landscaping applications. The plant's fibers were traditionally used by the Maori people for weaving.

  • ✓ Adds a dramatic architectural element to indoor or outdoor spaces.
  • ✓ Provides a bold statement with its striking foliage.
  • ✓ Offers a connection to New Zealand's natural heritage.
  • ✓ Can be used as a privacy screen outdoors.
  • ✓ Relatively low-maintenance once established (outdoors).
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Gunnera

Repotting Not applicable for indoor growing. Outdoors: Divide every few years to control spread.
Pruning Remove dead or damaged leaves as needed. Cut back flower spikes after blooming.
Fertilizing Balanced slow-release fertilizer in spring, followed by liquid fertilizer every 4-6 weeks during the growing season
Seasonal Care In winter, protect the crown of the plant with a thick layer of mulch or its own dried leaves. In summer, ensure consistent moisture and provide shade during the hottest part of the day.

New Zealand Flax

Repotting Every 1-2 years, or as needed, especially if the plant becomes root-bound. Use a larger pot with fresh well-draining soil.
Pruning Remove dead or damaged leaves as needed. Trim back to maintain shape.
Fertilizing Balanced liquid fertilizer diluted to half strength every 2-3 months during the growing season (spring and summer).
Seasonal Care In winter, reduce watering and ensure the plant receives as much light as possible. In summer, provide adequate moisture and consider moving the plant outdoors if possible.

🌞 Light Requirements

Gunnera

Full sun to partial shade

Low light tolerant: ❌ No

New Zealand Flax

Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily.

Low light tolerant: ❌ No

💧 Watering Needs

Gunnera

Requires consistently moist soil. Water deeply and regularly, especially during dry periods. Overwatering can lead to root rot, so ensure good drainage. Underwatering will cause the leaves to wilt and brown around the edges.

New Zealand Flax

Water thoroughly when the top inch of soil is dry. Overwatering can lead to root rot, especially indoors. Allow the soil to dry slightly between waterings. Signs of underwatering include drooping leaves; overwatering includes yellowing leaves and a soggy soil.

🌡️ Temperature & Humidity

Gunnera

Temperature: 10-25°C

Humidity: 60-80%

New Zealand Flax

Temperature: 10-27°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Gunnera

Gunnera

Gunnera manicata
Care: Expert Time: 30 minutes weekly during the growing season Beginner: No

Gardeners with large properties and a desire for a dramatic, architectural plant.

✅ Choose This Plant If...

  • You have a large garden with a pond or stream.
  • You want a dramatic, architectural plant to make a statement.
  • You live in a region with mild, wet summers.
  • You are prepared to provide consistent moisture and protection from harsh weather.
  • You enjoy the challenge of growing unique and demanding plants.

❌ Skip This Plant If...

  • You have a small garden or limited space.
  • You are looking for an easy-to-care-for plant.
  • You live in a dry climate with limited water resources.
  • You have pets that might ingest the plant.
  • You want an indoor plant.
📍 Ideal Location: Not suitable for indoor growing. Outdoors: Near a pond or stream in a large garden.
🎨 Style: Tropical, Architectural, Dramatic
🏠 Apartment Friendly: No
⚠️ The ASPCA lists Gunnera species as containing oxalates, which can be toxic to dogs, cats, and horses. Symptoms include excessive salivation, vomiting, diarrhea, and loss of appetite. All parts of the plant are considered toxic.
New Zealand Flax

New Zealand Flax

Phormium tenax
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced plant enthusiasts with very bright indoor spaces or those looking for a striking outdoor plant.

✅ Choose This Plant If...

  • You have a very bright, sunny indoor space and want a statement plant.
  • You live in a mild climate and want a striking evergreen for your garden.
  • You appreciate plants with architectural form and interesting foliage.
  • You are interested in the traditional uses of plants and their cultural significance.
  • You are an experienced plant owner looking for a challenging indoor plant project.

❌ Skip This Plant If...

  • You have limited indoor space.
  • You have pets that might ingest the plant.
  • You struggle to provide bright, direct sunlight.
  • You are a beginner plant owner.
  • You tend to overwater your plants.
📍 Ideal Location: Sunroom, conservatory, or a very bright south-facing window.
🎨 Style: Modern, Tropical, Architectural
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, New Zealand Flax is toxic to dogs, cats, and horses. The toxic principle is glycosides. Symptoms include vomiting, diarrhea, and depression.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Gunnera has fast growth, while New Zealand Flax grows moderate.

💡 Pro Tips For Comparing These Plants

Gunnera Care Tips

Gunnera manicata is an outdoor plant that requires expert care due to its large size and specific environmental needs. It is not suitable for indoor cultivation. It needs ample space, consistent moisture, and protection from harsh weather conditions. Challenges include managing its aggressive growth and preventing root rot.

  • Provide consistent moisture, especially during dry periods.
  • Protect the crown of the plant in winter with a thick layer of mulch.
  • Fertilize regularly during the growing season.
  • Monitor for pests and diseases and treat promptly.
  • Provide shade during the hottest part of the day to prevent leaf scorch.
❄️ Winter: In winter, cut back the leaves and use them to cover the crown of the plant as insulation. Add a thick layer of mulch for extra protection in colder climates. Ensure the soil is well-drained to prevent root rot.
☀️ Summer: In summer, provide consistent moisture and shade during the hottest part of the day. Fertilize regularly to support vigorous growth. Monitor for pests and diseases and treat promptly.

New Zealand Flax Care Tips

New Zealand Flax is primarily an outdoor plant and requires expert care to thrive indoors. It needs very bright light, well-draining soil, and careful watering to avoid root rot. Due to its size and light requirements, it's not well-suited for most indoor environments.

  • Provide at least 6 hours of direct sunlight daily indoors.
  • Ensure excellent drainage to prevent root rot.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Fertilize regularly during the growing season.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Reduce watering significantly. Ensure the plant receives as much light as possible. Protect from frost if grown outdoors in marginal climates.
☀️ Summer: Provide adequate moisture, especially during hot weather. Consider moving the plant outdoors to a sunny location if possible. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Gunnera

Common Issues: Root rot, Leaf scorch, Pests (slugs, snails)
Solutions: Ensure good drainage to prevent root rot. Provide shade during the hottest part of the day to prevent leaf scorch. Use slug and snail bait or handpick pests.

New Zealand Flax

Common Issues: Root rot, Scale insects, Mealybugs, Leaf spot
Solutions: Root rot: Improve drainage and reduce watering. | Scale insects: Wipe off with a damp cloth or use insecticidal soap. | Mealybugs: Treat with insecticidal soap or neem oil. | Leaf spot: Improve air circulation and remove affected leaves.

❓ Frequently Asked Questions — Comparing These Plants

Gunnera

What are the light requirements for Gunnera?

Gunnera thrives in bright, indirect light. Direct sunlight can scorch its large leaves, leading to unsightly brown spots and stunted growth. An east-facing window is often ideal, providing gentle morning sun followed by ample shade throughout the day. If grown indoors, supplement with grow lights if natural light is insufficient. Avoid placing Gunnera in a dimly lit area, as this can result in leggy growth and smaller, less vibrant leaves. Rotate the plant regularly to ensure even light exposure on all sides. If growing outdoors, choose a location that receives partial shade, particularly during the hottest part of the day.

How do I care for Gunnera?

Gunnera demands consistent moisture and high humidity to thrive. Position in bright, indirect light, avoiding direct sunlight which can scorch the leaves. Water generously, ensuring the soil remains consistently damp but not waterlogged. A well-draining soil mix rich in organic matter is crucial. Fertilize regularly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Prune away dead or damaged leaves to encourage new growth and maintain plant health. Provide adequate space for the plant to grow, as it can reach significant sizes. Consider using a humidifier or pebble tray to increase humidity levels, especially indoors. Protect from frost and extreme temperatures. Regularly inspect for pests and diseases, addressing any issues promptly.

How do I propagate Gunnera?

Gunnera can be propagated through stem cuttings, division, or air layering. For stem cuttings, take a cutting from a healthy stem and root it in water or moist potting mix. For division, carefully separate the rhizome into smaller sections, ensuring each section has roots and leaves. Plant each section in its own pot. Air layering involves wrapping a section of stem with moist sphagnum moss and covering it with plastic wrap until roots develop. Once roots have formed, cut the stem below the roots and plant in its own pot. Maintain high humidity and consistent moisture during the propagation process. Spring and early summer are the best times for propagation. Ensure proper sanitation to prevent fungal infections.

New Zealand Flax

What are the light requirements for New Zealand Flax?

New Zealand Flax prefers bright, indirect light. Placing it near an east-facing window is ideal, as it receives gentle morning sun. A south-facing window can also work, but be sure to filter the light with a sheer curtain to prevent leaf burn. Insufficient light can lead to leggy growth and faded leaf colors. Rotate the plant regularly to ensure even light exposure on all sides. If natural light is limited, supplement with grow lights to maintain healthy growth. Consider the intensity and duration of light, aiming for at least 6 hours of bright, indirect light per day. Consistent light exposure is crucial for vibrant foliage.

How do I care for New Zealand Flax?

New Zealand Flax thrives with bright, indirect light; avoid direct sunlight to prevent scorching. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels. Ideal temperatures range from 60-80°F (15-27°C). Fertilize during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength every 4-6 weeks. Repot every 2-3 years or when the plant becomes root-bound, using a well-draining potting mix. Prune dead or damaged leaves regularly to maintain appearance and promote healthy growth. Provide adequate ventilation to prevent fungal diseases. Monitor for pests such as spider mites and treat promptly. Stable conditions are key to success.

How do I propagate New Zealand Flax?

New Zealand Flax can be propagated through stem cuttings or division. For stem cuttings, take a healthy cutting from a mature plant, ensuring it has at least one node. Remove the lower leaves and place the cutting in water or directly into a well-draining potting mix. Keep the cutting moist and in a warm, bright location until roots develop. For division, carefully separate the root ball of a mature plant into smaller sections, ensuring each section has healthy roots and foliage. Plant each section in its own pot with well-draining potting mix. Water thoroughly and keep in a warm, bright location. Propagation is best done in spring or summer. Use rooting hormone to improve success rates.

Last updated: May 15, 2026 — Plant care data reviewed and verified by our editorial team.