Renowned for adaptability to various climates, the crown of thorns is a popular houseplant. The plant has religious significance to Christians due to the belief that this plant was used in Jesus Christ's crown of thorns.
These plants are resilient, tolerating dry air and fluctuating temperatures well. They make the perfect addition to any home garden and grow well with other succulents or cacti that share similar light and water requirements.
Crown of Thorns Overview
Crown of thorns, crown-of-thorns, Christ plant, Christ thorn
3-6 ft. tall outdoors, 2 ft. tall indoors; 18-36 in. wide
Spring, summer, fall, winter
Red, orange, pink, yellow, white
Toxic to people and pets
What Is A Crown of Thorns?
The Crown of Thorns plant is a succulent shrub known for its thorny stems and clusters of small, colorful flowers. The plant typically grows up to 3 feet tall, though some varieties can reach up to 6 feet in height. The stems are thick and succulent, often armed with sharp thorns.
While this plant can grow to 5 or 6 feet tall in Madagascar, the country of its origin, it can only grow up to 3 feet in the US. Like many other plants in the Euphorbia genus, the crown of thorns contains a milky sap that can be irritating to the skin and toxic if ingested.
The crown of thorns can be grown both indoors and outdoors, depending on the climate. Indoors, it thrives in bright, indirect light and prefers well-draining soil. Outdoors, they can be cultivated in warm, arid climates.
Crown of Thorns Care
Crown of thorns plant is generally low-maintenance, but it does require attention to a few key factors. Whether grown indoors or outdoors, it prefers bright, indirect light and well-draining soil.
Indoor plants may benefit from occasional misting to increase humidity, especially in dry climates or heated indoor environments. On the other hand, outdoor plants should be protected from extreme temperatures and frost, as they prefer warmer conditions.
Crown of thorns thrive in bright light, so place them in a location where they can receive at least 4 to 6 hours of direct sunlight each day. However, they can tolerate some partial shade, especially during the hottest part of the day in very warm climates.
These plants prefer warm temperatures and are sensitive to cold. Ideally, keep them in an environment where temperatures remain between 65°F and 85°F (18°C and 29°C) year-round. Protect them from temperatures below 50°F (10°C), as they are sensitive to frost.
Crown of thorns plants are native to Madagascar, where they typically grow in warm, arid climates with low humidity. As a result, they are well-adapted to dry conditions and can tolerate relatively low humidity levels.
Crown of thorns are succulents and are drought-tolerant, so it's essential not to overwater them. Allow the soil to dry out partially between waterings. Water deeply but infrequently, and ensure that the soil has good drainage to prevent waterlogging, which can lead to root rot. During the growing season (spring and summer), water when the top inch of soil feels dry. In the dormant season (fall and winter), reduce watering to allow the plant to rest.
Use a well-draining potting mix specifically formulated for cacti and succulents, or make your own by combining equal parts of potting soil, sand, and perlite. This type of soil prevents water from pooling around the roots, reducing the risk of root rot.
Feed crown of thorns plants sparingly during the growing season with a balanced liquid fertilizer diluted to half strength. Apply fertilizer every 4 to 6 weeks to promote healthy growth and flowering. Avoid fertilizing during the dormant season.
Thorn of crowns pruning is typically done in early spring, just before the plant enters its active growth phase. This timing allows the plant to recover quickly from pruning and promotes new growth and flowering during the growing season. However, light pruning can be done throughout the year as needed to remove dead or damaged growth.
Use sharp, clean pruning shears or scissors to make precise cuts without damaging the plant. Disinfect the pruning tools before and after use to prevent the spread of diseases or pests.
Identify the stems or branches that need to be pruned, focusing on removing those that are dead, crossing, or overcrowded. Make clean cuts just above a leaf node or branch junction, using sharp pruning shears.
To deadhead spent flowers, simply pinch or snip off the faded blooms at their base. This encourages the plant to produce new flower buds and prolongs the flowering period.
If the plant is overly dense or crowded, you can selectively thin out some of the stems to improve air circulation and light penetration.
When pruning the crown of thorns plants, it's essential to wear gloves to protect your hands from the plant's sharp thorns and latex sap, which can irritate the skin and cause allergic reactions in some individuals.
Propagating Crown of Thorns
The most popular method of propagating Crown of Thorns is stem cuttings. It's easy, effective, and much faster than the alternative method of seed propagation. Spring is widely considered the ideal time to propagate crowns of thorns due to the warmer temperatures and longer daylight hours that aid in root development. However, propagation can be successful year-round as long as you provide the right conditions.
Here's how to propagate stem cutting:
Gather sharp shears, gloves, a pot with drainage, cactus mix, and a plastic bag (optional).
Choose a healthy, pencil-thick stem (3–4 inches) with a node. Cut at a 45° angle below a node and let the sap dry.
Fill the pot with the moist cactus mix, leaving space.
Dip the cut end in rooting hormone (optional), and insert 1-2 inches of firm soil.
Cover the pot loosely with a plastic bag. (optional)
Provide bright, indirect light and water sparingly when the soil dries. Remove the bag when new growth appears (4–8 weeks).
Rooting takes time.
Pinch new top growth for bushier plants.
Potting and Repotting
Thorn crown plant requires a pot with drainage holes at the bottom to prevent waterlogging, as crown of thorn plants are susceptible to root rot in overly wet conditions. Select a pot that is slightly larger than the plant's current container, allowing room for root growth without being excessively large.
Repot crown of thorns plants every 2 to 3 years, or when they outgrow their current container. Spring is the best time for repotting, just before the plant enters its active growth phase. To repot, gently remove the plant from its current pot, taking care not to damage the roots. Shake off excess soil from the roots and inspect them for signs of rot or damage.
Place a layer of fresh potting mix in the bottom of the new pot, then position the plant in the center, making sure it sits at the same depth as it was in the previous pot. Water the plant thoroughly after repotting to help settle the soil around the roots.
Euphorbia milii requires special winter care in cold regions or if the plant is grown in containers outdoors. For outdoor crown of thorns in containers, transition it indoors before the first frost. Place it in a bright location near a sunny window where it can receive at least 4 to 6 hours of sunlight per day.
These plants may enter a period of dormancy during the winter, during which growth slows down significantly. This is normal behavior for many plants during the colder months. Continue to provide basic care and monitor the plant for any signs of stress or disease.
Common Pests & Plant Diseases
While the crown of thorns plant is generally a low-maintenance plant, it can still be susceptible to some pests and diseases. Here are some of the most common ones to watch out for:
Spider mites: These tiny pests are difficult to see with the naked eye, but they can cause leaves to yellow and drop. You can control them by spraying the plant with insecticidal soap or neem oil.
Mealybugs: These small, white insects suck the sap out of leaves and stems, causing them to become distorted and stunted. Dip a cotton swab in rubbing alcohol, or use insecticidal soap or neem oil to remove it.
Scale insects: These hard-bodied insects appear as small bumps on the stems and leaves. Scrape them off with a fingernail or use insecticidal soap or neem oil.
Root rot: This fungal disease is caused by overwatering. Symptoms include wilting leaves, yellowing leaves, and stunted growth. If you catch it early, you may be able to save the plant by repotting it in fresh, well-draining soil and watering less often.
Leaf spot disease: This fungal disease causes brown or black spots to appear on the leaves. Improve air circulation around the plant and remove any infected leaves to prevent it.
Botrytis: This fungal disease causes gray mold to grow on the leaves and flowers. It is most common in cool, humid conditions. You can control it by improving air circulation and removing any infected parts of the plant.
Early detection and intervention are key. It is crucial to regularly inspect your plant, address issues promptly, and maintain proper care to keep your crown of thorns thriving.
How to Get Crown of Thorns to Bloom
Crowns of thorns require providing the right growing conditions, proper care, and sometimes a little encouragement to bloom. Sometimes, stressing the plant slightly can encourage blooming. This can be done by slightly reducing water or by subjecting the plant to slightly cooler temperatures for a short period (not below 50°F or 10°C).
Crown of thorns typically blooms year-round under optimal conditions, but its peak blooming period is during the spring and summer months. However, with proper care and favorable growing conditions, it can produce flowers sporadically throughout the year.
How Long Does Crown of Thorns Bloom?
Crown of thorns can potentially bloom year-round if given proper care. However, blooms are most abundant in spring and summer. Individual blooms last 1-2 weeks, with the overall flowering period spanning several weeks. In ideal conditions, even repeat blooms throughout the year are possible.
What Do Crown of Thorns Flowers Look and Smell Like?
The flowers are small and clustered, typically measuring around 1 inch in diameter. They come in various colors, including red, pink, yellow, and white. The flowers have a subtle, sweet fragrance, but the scent is generally not strong or overpowering.
Crown of Thorns Types
Crown of thorns euphorbia come in various cultivars and hybrids, each with its own unique characteristics, such as flower color, growth habit, and size. These plants has cultural significance in various parts of the world. In Christianity, it is believed to be the plant used to make the crown of thorns worn by Jesus during the crucifixion, hence the name.
Likewise, in some cultures, it is considered a symbol of good luck and prosperity.
Red Crown of Thorns: The most common and traditional variety, known for its vibrant red flowers.
Yellow Crown of Thorns: Produce bright yellow flowers, adding a cheerful pop of color to gardens and indoor spaces.
Pink Crown of Thorns: Popular for their soft, pastel-colored blooms.
Variegated Crown of Thorns: These cultivars feature foliage with variegated patterns of white, cream, or yellow, adding visual interest even when the plant is not in bloom.
Dwarf Crown of Thorns: Compact and low-growing, making them ideal for small spaces or container gardens.
Double-flowered Crown of Thorns: Densely packed petals, giving the appearance of multiple layers of petals.
Hybrid Varieties: Plant breeders have developed numerous hybrid cultivars by crossing different varieties of the crown of thorns.
Besides the different types of crown of thorns succulents, learn about the types of succulents that will redefine your shelf.
Challenges With Crown of Thorns
Flowers with thorns is a resilient and low-maintenance plant, but it can still face some common problems. These issues may arise due to environmental factors, pests, diseases, or improper care practices. Here are some of the common problems:
This can be caused by various factors, including overwatering, underwatering, or nutrient deficiencies. Adjust watering and fertilization practices as needed, and ensure the plant is receiving adequate light.
Insufficient light can cause the plant to become leggy, with elongated stems and sparse foliage. Move the plant to a brighter location or provide supplemental lighting to encourage compact growth.
Lack of Blooming
If the plant fails to bloom, it may be due to insufficient light, improper pruning, or inadequate fertilization. Provide adequate sunlight, prune the plant to encourage branching, and fertilize with a balanced fertilizer high in phosphorus to promote flowering.
Stressors such as temperature fluctuations, improper watering, or pests can cause the crown of thorns to drop leaves. Maintain consistent growing conditions and address any underlying issues to prevent excessive leaf drop.
Yes, these plants can grow both indoors and outdoors. They prefer warm climates and are suitable for outdoor cultivation in USDA hardiness zones 9 to 11. In cooler climates, they can be grown as houseplants indoors, where they can still thrive with proper care and sunlight.
Can I grow a crown of thorns plant from seed?
Yes, crown of thorns plants can be grown from seed, but they typically take longer to mature and bloom compared to propagation from stem cuttings.
Can I grow a crown of thorns plant in a hanging basket?
Yes, crown of thorns plants can be grown in hanging baskets, but they may require more frequent watering due to the smaller soil volume and increased exposure to air.