Greater Celandine vs New Zealand Flax Plant Comparison

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

Greater Celandine

Greater Celandine

Chelidonium majus

VS
New Zealand Flax

New Zealand Flax

Phormium tenax

Greater Celandine

Greater Celandine

Chelidonium majus

Greater celandine is a herbaceous perennial plant typically growing to a height of 30-120 cm. It features deeply lobed, bluish-green leaves and produces small, yellow flowers in umbel-like clusters from spring to autumn. The plant is characterized by its orange-yellow latex sap, which exudes when stems are broken. It is primarily an outdoor plant, often found in waste places and along roadsides. People sometimes grow it for its purported medicinal properties, though caution is advised due to its toxicity.

Papaveraceae Europe and Western Asia; naturalized in North America and other regions.
✨ Features: Orange-yellow latex sap with purported medicinal properties (use with extreme caution and under professional guidance only).
📖 Read Complete Greater Celandine 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 Greater Celandine New Zealand Flax
Light Partial shade to full sun. Requires at least 4 hours of direct sunlight outdoors. Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily.
Watering Every 7-10 days during the growing season, less frequently in winter. Every 1-2 weeks, depending on light and temperature. Less frequent in winter.
Humidity 30-50% 30-50%
Temperature 10-24°C 10-27°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height 30-120 cm (outdoor) 1-2 meters indoors (much larger outdoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-drained soil, such as a loamy or sandy 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 15 minutes weekly (outdoor) 30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Greater Celandine

Scientific Name Chelidonium majus
Family Papaveraceae
Native To Europe and Western Asia; naturalized in North America and other regions.
Also Known As Greater celandine, Tetterwort, Swallowwort, Wartweed
Leaves Pinnately lobed, bluish-green leaves, 5-20 cm long, with rounded or obtuse lobes. The leaves are alternate and have a somewhat hairy texture.
Flowers Small, bright yellow flowers, about 1-2 cm in diameter, arranged in umbel-like clusters. Blooms from spring to autumn outdoors. 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

Greater Celandine

Height 30-120 cm (outdoor)
Spread 30-60 cm (can spread via seeds)
Growth Rate Moderate
Growth Pattern Erect, branching herbaceous perennial with a clumping habit. Spreads primarily through seed dispersal.

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

Greater Celandine

Methods: Seed, Root division

Difficulty: Moderate

Tips: Sow seeds in spring or autumn. Divide established plants in early spring or late autumn. Ensure good drainage for successful propagation.

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

Greater Celandine

The plant's distinctive orange-yellow sap is a key identifier. Its historical use in traditional medicine, though requiring extreme caution, sets it apart from many other garden plants.

  • ✓ Attracts pollinators
  • ✓ Adds visual interest to a naturalized garden
  • ✓ Historically used in traditional medicine (with extreme caution)
  • ✓ Can be used as a ground cover in suitable conditions
  • ✓ Provides a unique texture to the garden with its lobed leaves.
  • ⚠️ 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

Greater Celandine

Repotting Not applicable for indoor growing, as it is not recommended. If grown in a container outdoors, repot every 2-3 years.
Pruning Remove dead or damaged foliage regularly. Cut back stems after flowering to encourage new growth.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, applied every 4-6 weeks during the growing season.
Seasonal Care In spring and summer, ensure adequate watering and fertilization. In autumn, reduce watering and remove dead foliage. In winter, provide protection from frost in colder climates.

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

Greater Celandine

Partial shade to full sun. Requires at least 4 hours of direct sunlight outdoors.

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

Greater Celandine

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Reduce watering during the dormant winter period. Signs of overwatering include yellowing leaves and a soggy soil. Underwatering is indicated by wilting and dry, crispy leaves.

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

Greater Celandine

Temperature: 10-24°C

Humidity: 30-50%

New Zealand Flax

Temperature: 10-27°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Greater Celandine

Greater Celandine

Chelidonium majus
Care: Expert Time: 15 minutes weekly (outdoor) Beginner: No

Experienced gardeners who understand its toxicity and can provide the necessary outdoor conditions.

✅ Choose This Plant If...

  • You have a specific outdoor area with partial shade
  • You are an experienced gardener familiar with toxic plants
  • You are interested in traditional medicinal uses (with extreme caution and professional guidance)
  • You have a well-drained garden bed
  • You want to attract certain pollinators to your garden.

❌ Skip This Plant If...

  • You have pets or small children who might ingest the plant
  • You are a beginner gardener
  • You are looking for an easy-to-grow indoor plant.
📍 Ideal Location: Outdoor garden or naturalized area with partial shade.
🎨 Style: Cottage garden, Naturalized garden
🏠 Apartment Friendly: No
⚠️ All parts of the plant are toxic, especially the roots and sap. Contains isoquinoline alkaloids. Can cause gastrointestinal upset (vomiting, diarrhea), skin irritation, and potentially neurological symptoms in dogs, cats, and horses. Contact with the sap can cause skin irritation in humans as well.
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

🌿

Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.

💡 Pro Tips For Comparing These Plants

Greater Celandine Care Tips

Greater celandine is primarily an outdoor plant and is challenging to grow indoors. It requires specific light conditions and well-drained soil. Due to its toxicity, it's crucial to handle it with care and keep it away from pets and children. It is not recommended as an indoor plant.

  • Wear gloves when handling the plant to avoid skin irritation from the sap.
  • Provide well-drained soil to prevent root rot.
  • Monitor for pests and diseases regularly.
  • Deadhead spent flowers to encourage continued blooming.
  • Keep the plant away from areas frequented by pets and children.
❄️ Winter: In colder climates, the plant may die back to the ground in winter. Provide a layer of mulch for protection. Reduce watering significantly.
☀️ Summer: Ensure adequate watering during hot, dry periods. Provide some shade during the hottest part of the day to prevent leaf scorch.

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

Greater Celandine

Common Issues: Aphids, Root rot, Powdery mildew
Solutions: Aphids: Insecticidal soap or neem oil. Root rot: Improve drainage and reduce watering. Powdery mildew: Fungicide and improve air circulation.

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

Greater Celandine

What are the light requirements for Greater Celandine?

Greater Celandine prefers partial shade to full shade, thriving in locations that receive dappled sunlight or filtered light throughout the day. Avoid direct sunlight, especially during the hottest part of the day, as it can scorch the leaves. An east-facing location or a spot under a tree canopy is ideal. Insufficient light can result in leggy growth and reduced flowering. If growing indoors, place the plant near a north-facing window or provide artificial light with a grow light for several hours per day. Monitor the plant for signs of stress, such as pale leaves or sunburn, and adjust the light accordingly.

How do I care for Greater Celandine?

Greater Celandine thrives in partial shade to full shade and prefers moist, well-drained soil. Water regularly, especially during dry periods, but avoid overwatering to prevent root rot. Fertilize sparingly with a balanced liquid fertilizer diluted to half strength, only during the growing season (spring and summer) to encourage blooming. Deadhead spent flowers to promote further blooming and prevent excessive self-seeding. Monitor for pests such as aphids and slugs, and treat accordingly. Prune back any dead or damaged foliage to maintain plant health and appearance. Provide adequate air circulation to prevent fungal diseases. Mulch around the base of the plant to retain moisture and suppress weeds. Repotting is rarely necessary as Greater Celandine prefers to be slightly root-bound.

How do I propagate Greater Celandine?

Greater Celandine can be propagated through division. In early spring or fall, carefully dig up the plant and gently separate the roots into smaller clumps, ensuring each clump has healthy roots and foliage. Replant the divisions in well-draining soil and water thoroughly. Keep the soil consistently moist until new growth appears. Stem cuttings are not a reliable method for propagation. Greater Celandine does not produce keikis. Division is the most effective and straightforward way to propagate this plant, allowing you to expand your collection or share it with others. Ensure the divisions are planted in a location with similar light and soil conditions as the parent plant.

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: April 21, 2026 — Plant care data reviewed and verified by our editorial team.