Crown of Thorns vs New Zealand Flax Plant Comparison
Compare these two plants side by side — care needs, key differences, and which is right for your home.
Crown of Thorns
Euphorbia milii
Euphorbia milii, commonly known as Crown of Thorns, is a succulent shrub characterized by its thorny stems and vibrant bracts surrounding small, inconspicuous flowers. Native to Madagascar, it is a popular ornamental plant grown for its drought tolerance and long-lasting blooms. It typically grows as a sprawling shrub, reaching up to 1-2 meters in height. While it can be grown indoors, it thrives best with ample sunlight, often making it more suitable as an outdoor plant in warmer climates. People grow it for its unique appearance and relatively easy care.
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.
Quick Plant Comparison
| Feature | Crown of Thorns | New Zealand Flax |
|---|---|---|
| Light | Requires at least 4-6 hours of direct sunlight daily. Insufficient light will result in leggy growth and reduced flowering. | Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily. |
| Watering | Every 2-3 weeks, depending on environmental conditions and pot size. | Every 1-2 weeks, depending on light and temperature. Less frequent in winter. |
| Humidity | 30-50% | 30-50% |
| Temperature | 18-27°C | 10-27°C |
| Care Level | Moderate | Expert |
| Growth Rate | Slow | Moderate |
| Max Height | 0.3-0.6 meters (indoors) | 1-2 meters indoors (much larger outdoors) |
| Pet Safety | ❌ Toxic To Pets | ❌ Toxic To Pets |
| Soil | Well-draining succulent or cactus mix | Well-draining soil is crucial. A mix of potting soil, sand, and perlite is suitable. |
| Beginner Friendly | With Caution | ❌ No |
| Weekly Maintenance | 10 minutes weekly | 30 minutes weekly |
🔬 Botanical Information — Comparing These Plants
Crown of Thorns
| Scientific Name | Euphorbia milii |
|---|---|
| Family | Euphorbiaceae |
| Native To | Madagascar |
| Also Known As | Crown of Thorns, Christ Plant, Christ Thorn |
| Leaves | The leaves are small, oval-shaped, and typically bright green. They are deciduous, meaning they may drop off during periods of stress or dormancy, especially in winter. |
| Flowers | It can flower indoors, but flowering is more prolific with ample sunlight. The true flowers are small and inconspicuous, surrounded by colorful bracts that can be red, pink, yellow, or white. |
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
Crown of Thorns
New Zealand Flax
🌱 Propagation — Comparing Plant Growth
Crown of Thorns
Methods: Stem cuttings
Difficulty: Easy
Tips: Allow the cut end to callus over for a few days before planting in well-draining soil. Use rooting hormone for better success.
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
Crown of Thorns
The Crown of Thorns is unique due to its thorny stems and the colorful bracts that surround its small flowers. Unlike many flowering plants, the bracts provide color for extended periods, making it a long-lasting ornamental plant.
- ✓ Drought tolerance makes it easy to care for
- ✓ Long-lasting blooms add color to your space
- ✓ Unique appearance provides visual interest
- ✓ Can tolerate neglect, making it suitable for busy individuals
- ✓ Adds a touch of history and symbolism to your plant collection
- ⚠️ 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
Crown of Thorns
New Zealand Flax
🌞 Light Requirements
Crown of Thorns
Requires at least 4-6 hours of direct sunlight daily. Insufficient light will result in leggy growth and reduced flowering.
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
Crown of Thorns
Allow the soil to dry out completely between waterings. Overwatering can lead to root rot. Water thoroughly when the soil is dry to the touch. Signs of overwatering include yellowing leaves and stem rot. Underwatering will cause leaf drop and shriveling.
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
Crown of Thorns
Temperature: 18-27°C
Humidity: 30-50%
New Zealand Flax
Temperature: 10-27°C
Humidity: 30-50%
🤔 Which Plant Is Right For You?
Crown of Thorns
Euphorbia miliiExperienced plant owners who can provide bright light and are aware of the plant's toxicity.
✅ Choose This Plant If...
- You want a drought-tolerant plant that flowers for a long period.
- You have a sunny location where the plant can thrive.
- You are experienced with caring for succulents and understand their watering needs.
- You are looking for a unique and interesting plant with a historical connection.
- You can keep the plant away from pets and children due to its toxicity.
❌ Skip This Plant If...
- You have pets or small children who might ingest the plant.
- You cannot provide adequate sunlight.
- You tend to overwater plants.
- You are looking for a low-maintenance plant that thrives in low-light conditions.
New Zealand Flax
Phormium tenaxExperienced 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.
🎯 Quick Verdict
⚡ Key Differences Between These Plants
Crown of Thorns is rated Moderate care level, while New Zealand Flax is Expert.
Crown of Thorns has slow growth, while New Zealand Flax grows moderate.
💡 Pro Tips For Comparing These Plants
Crown of Thorns Care Tips
Crown of Thorns requires bright sunlight and well-draining soil. Overwatering is a common issue. It can be grown indoors with sufficient light, but may not flower as profusely as when grown outdoors. Toxicity to pets is a significant concern.
- Provide at least 4-6 hours of direct sunlight daily for optimal growth and flowering.
- Allow the soil to dry out completely between waterings to prevent root rot.
- Use a well-draining succulent or cactus mix to ensure proper drainage.
- Fertilize sparingly during the growing season with a balanced liquid fertilizer.
- Wear gloves when pruning or handling the plant to avoid skin irritation from the sap.
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.
⚠️ Common Problems & Solutions — Plant Care Comparison
Crown of Thorns
New Zealand Flax
❓ Frequently Asked Questions — Comparing These Plants
Crown of Thorns
What are the light requirements for Crown of Thorns?
Crown of Thorns requires bright, direct sunlight to thrive. Ideally, place it in a south-facing window where it can receive at least 4-6 hours of sunlight per day. Insufficient light can lead to leggy growth, reduced flowering, and a loss of vibrancy in the bracts. If you don’t have a sufficiently sunny window, consider supplementing with a grow light. Rotate the plant regularly to ensure even light exposure on all sides. During the summer months, you can move your Crown of Thorns outdoors to a sunny location, but be sure to acclimate it gradually to avoid sunburn. The plant’s ability to flower profusely depends on adequate light.
How do I care for Crown of Thorns?
Crown of Thorns thrives on neglect, making it an easy-care succulent. Plant it in well-draining soil, such as a cactus mix, to prevent root rot. Provide it with bright, direct sunlight for at least 4-6 hours daily. Water sparingly, allowing the soil to dry completely between waterings. Reduce watering frequency during the dormant winter months. Fertilize lightly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Maintain a room temperature between 65-75°F (18-24°C). Avoid overwatering, as this is the most common cause of problems. Repot every 2-3 years, or when the plant becomes root-bound. Prune to maintain shape and remove dead or damaged stems. Be cautious of the milky sap, which can be irritating to the skin and eyes.
How do I propagate Crown of Thorns?
Crown of Thorns can be propagated through stem cuttings. Allow the cut end to callous over for several days before planting in well-draining soil. Keep the soil slightly moist until roots develop. Leaf cuttings are not generally successful. Offsets, or small plantlets that grow at the base of the plant, can be carefully separated and potted individually. Wear gloves to protect your skin from the irritating sap. Rooting hormone can improve the success rate of stem cuttings. Provide bright, indirect light during the rooting process. Avoid overwatering, as this can lead to rot. Propagation is best done during the growing season (spring and summer).
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 1, 2026 — Plant care data reviewed and verified by our editorial team.