Crown of Thorns vs Flax Lily Plant Comparison

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

Crown of Thorns

Crown of Thorns

Euphorbia milii

VS
Flax Lily

Flax Lily

Dianella tasmanica

Crown of Thorns

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.

Euphorbiaceae Madagascar
✨ Features: Long-lasting blooms, drought tolerance
📖 Read Complete Crown of Thorns Guide
Flax Lily

Flax Lily

Dianella tasmanica

Dianella tasmanica, commonly known as the Flax Lily, is a rhizomatous perennial herb native to Tasmania. It features strappy, arching leaves that resemble flax, hence the name. It typically grows outdoors in shaded or partially shaded areas. While it can be grown indoors, it requires specific conditions to thrive and may not flower as readily as when grown outdoors. People grow it for its attractive foliage, clumping habit, and relatively low maintenance when grown in suitable conditions.

Asphodelaceae Tasmania, Australia
✨ Features: Attractive foliage, clumping habit
📖 Read Complete Flax Lily Guide

Quick Plant Comparison

Feature Crown of Thorns Flax Lily
Light Requires at least 4-6 hours of direct sunlight daily. Insufficient light will result in leggy growth and reduced flowering. Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day.
Watering Every 2-3 weeks, depending on environmental conditions and pot size. Every 1-2 weeks, depending on environmental conditions and pot size.
Humidity 30-50% 40-60%
Temperature 18-27°C 15-24°C
Care Level Moderate Moderate
Growth Rate Slow Moderate
Max Height 0.3-0.6 meters (indoors) 0.5-1 meter (indoors, typically smaller)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining succulent or cactus mix Well-draining potting mix with added perlite or sand.
Beginner Friendly With Caution With Caution
Weekly Maintenance 10 minutes weekly 10 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.

Flax Lily

Scientific Name Dianella tasmanica
Family Asphodelaceae
Native To Tasmania, Australia
Also Known As Flax Lily, Tasman Flax Lily
Leaves The leaves are long, linear, and strap-like, typically 30-90 cm long and 1-3 cm wide. They are usually green, but some cultivars have variegated foliage with stripes of yellow or white. The texture is smooth and slightly glossy.
Flowers It may flower indoors, but it is more common when grown outdoors. The flowers are small, star-shaped, and blue or purple, followed by blue or purple berries.

📏 Size & Growth — Plant Comparison

Crown of Thorns

Height 0.3-0.6 meters (indoors)
Spread 0.3-0.5 meters
Growth Rate Slow
Growth Pattern The plant grows as an upright, branching shrub with thick, thorny stems. It can become somewhat sprawling as it matures, especially if not pruned regularly.

Flax Lily

Height 0.5-1 meter (indoors, typically smaller)
Spread 0.5-1 meter (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern It grows in a clumping habit, with leaves arching outwards from the base. It spreads via rhizomes, gradually expanding its footprint.

🌱 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.

Flax Lily

Methods: Division, Seed

Difficulty: Easy

Tips: Divide rhizomes in spring or early summer. Ensure each division has healthy roots and leaves. Sow seeds in spring after soaking them in warm 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

Flax Lily

Its strappy, arching leaves give it a unique texture and appearance. It spreads via rhizomes, forming clumps over time. While it can be grown indoors, it is primarily an outdoor plant.

  • ✓ Adds a touch of greenery to indoor spaces.
  • ✓ Relatively low maintenance.
  • ✓ Can be easily propagated.
  • ✓ Provides a calming, natural aesthetic.
  • ✓ Tolerates some neglect.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Crown of Thorns

Repotting Every 2-3 years, or when the plant becomes root-bound.
Pruning Prune to maintain shape and remove dead or damaged stems. Wear gloves to avoid skin irritation from the sap.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, applied every 2-3 months during the growing season (spring/summer).
Seasonal Care Reduce watering in winter. Provide bright light year-round. Protect from frost.

Flax Lily

Repotting Every 1-2 years, or when the plant becomes root-bound. Divide the rhizomes during repotting to control spread.
Pruning Remove dead or damaged leaves as needed. Trim back excessive growth to maintain shape.
Fertilizing Balanced liquid fertilizer diluted to half strength, every 2-3 months during the growing season (spring and summer).
Seasonal Care Reduce watering in winter when growth slows. Provide adequate light during shorter days. In summer, ensure adequate moisture and protect from intense direct sunlight.

🌞 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

Flax Lily

Bright, indirect light. Avoid direct sunlight, especially during the hottest part of the day.

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.

Flax Lily

Water thoroughly when the top inch of soil feels dry to the touch. Ensure good drainage to prevent root rot. Overwatering can lead to yellowing leaves and root rot, while underwatering can cause the leaves to droop and brown at the tips.

🌡️ Temperature & Humidity

Crown of Thorns

Temperature: 18-27°C

Humidity: 30-50%

Flax Lily

Temperature: 15-24°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Crown of Thorns

Crown of Thorns

Euphorbia milii
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Experienced 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.
📍 Ideal Location: South-facing window or sunny patio
🎨 Style: Desert, Southwestern, Eclectic
🏠 Apartment Friendly: Limited
⚠️ All parts of the plant contain a milky sap that is toxic to dogs, cats, and horses. Symptoms include oral irritation, vomiting, diarrhea, and skin irritation upon contact. According to the ASPCA, ingestion can cause gastrointestinal upset and skin irritation.
Flax Lily

Flax Lily

Dianella tasmanica
Care: Moderate Time: 10 minutes weekly Beginner: With-caution

Someone looking for a low-maintenance plant with attractive foliage, but who is aware of its toxicity to pets.

✅ Choose This Plant If...

  • You want a plant with attractive, grass-like foliage.
  • You have a location with bright, indirect light.
  • You are looking for a relatively low-maintenance plant.
  • You want a plant that can be easily propagated by division.
  • You understand its toxicity to pets and can keep it out of their reach.

❌ Skip This Plant If...

  • You have pets that may ingest plants.
  • You have a very dark home with limited natural light.
  • You are prone to overwatering plants.
📍 Ideal Location: Bright bathroom, living room near a window with filtered light, or a covered patio.
🎨 Style: Modern, Tropical, Bohemian
🏠 Apartment Friendly: Yes
⚠️ According to the ASPCA, Dianella species are toxic to dogs, cats, and horses. The toxic principle is not explicitly stated, but symptoms include vomiting and diarrhea.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Flax Lily

⚡ Key Differences Between These Plants

📈

Crown of Thorns has slow growth, while Flax Lily 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.
❄️ Winter: Reduce watering significantly during the winter months. Ensure the plant receives as much sunlight as possible. Protect from frost.
☀️ Summer: Water more frequently during the summer growing season, but still allow the soil to dry out between waterings. Provide adequate ventilation to prevent fungal diseases.

Flax Lily Care Tips

Flax Lily is relatively easy to care for, but requires bright, indirect light and well-draining soil. Overwatering is a common problem. It may not flower indoors as readily as outdoors. It spreads via rhizomes, so repotting may be needed more frequently than other houseplants.

  • Allow the top inch of soil to dry out before watering.
  • Provide bright, indirect light to maintain vibrant foliage.
  • Fertilize sparingly during the growing season.
  • Monitor for pests like spider mites and treat promptly.
  • Repot every 1-2 years to prevent root-bound conditions.
❄️ Winter: Reduce watering frequency during winter as growth slows down. Ensure the plant still receives adequate light. Avoid placing it near cold drafts.
☀️ Summer: Provide adequate moisture during the warmer months. Protect from intense direct sunlight to prevent leaf burn. Increase humidity if possible.

⚠️ Common Problems & Solutions — Plant Care Comparison

Crown of Thorns

Common Issues: Root rot, spider mites, mealybugs, leaf drop
Solutions: Root rot: Improve drainage, reduce watering frequency. Spider mites: Insecticidal soap or neem oil. Mealybugs: Isopropyl alcohol or insecticidal soap. Leaf drop: Adjust watering and light levels.

Flax Lily

Common Issues: Root rot, brown leaf tips, spider mites
Solutions: Root rot: Ensure proper drainage and avoid overwatering. Treat with fungicide if necessary.|Brown leaf tips: Increase humidity or water more consistently. Avoid letting the soil dry out completely.|Spider mites: Treat with insecticidal soap or neem oil.

❓ 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).

Flax Lily

What are the light requirements for Flax Lily?

Flax Lily flourishes in bright, indirect light. Direct sunlight can scorch its leaves, so avoid placing it in south-facing windows without some form of shading. An east or west-facing window is ideal, where it can receive gentle morning or afternoon light. If your plant is in a lower-light environment, its growth may be slower, and the colors may appear less vibrant. Rotate your plant regularly to ensure even light exposure on all sides. Insufficient light can lead to leggy growth and faded foliage.

How do I care for Flax Lily?

Flax Lily thrives in bright, indirect light but can tolerate lower light conditions. Water when the top inch of soil feels dry, ensuring the pot has good drainage to prevent root rot. Maintain moderate humidity levels, especially during dry seasons, by misting the plant regularly or using a humidifier. Fertilize monthly during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength. Repot every 1-2 years, or when the plant becomes root-bound, using a well-draining potting mix. Prune away any dead or yellowing leaves to maintain its appearance and health. Protect from frost and extreme temperatures. Proper watering, light, and humidity are key to a thriving Flax Lily.

How do I propagate Flax Lily?

Flax Lily can be propagated through division, stem cuttings, and air layering.

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