Crown of thorns (Euphorbia milii)

Also known as: Christ thorn

*Euphorbia milii*, also called the crown of thorns or Christ thorn, is thought to be linked to the biblical crown of thorns. This plant requires full sunlight and temperatures above 10°C to thrive.

In This Article

Care Tips Water Sunlight Temperature Soil Fertilize Prune Propagation Repotting Toxicity

Plant Comprehensive Care Guide: Beginner's Introduction and Key Details

Perfect for beginners starting their plant care journey

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10 Secrets to Making Crown of thorns Grow Faster (A Must-Read for Beginners)

Advanced tips to accelerate your plant's growth

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Care "Black Tech": 10 Little-Known Highly Effective Maintenance Tips

Expert-level techniques for optimal plant care

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Attributes of Crown of thorns

Lifespan

Perennial

Plant Type

Succulent, Shrub

Plant Height

90 cm to 1.8 m

Spread

45 cm to 90 cm

Leaf Color

Green

Flower Size

1.2 cm

Flower Color

Red Yellow Pink White Gold

Images of Crown of thorns

Quickly Identify Crown of thorns

Fleshy, bright green leaves with smooth margins, appearing vibrant

Stems armed with thick, black spines, exhibiting a 5-6 sided shape

Greenish inflorescences with red or yellow bracts, blooming on long peduncles

Tiny, green, unisexual flowers enclosed in a 5-lobed involucre

Leaves typically 2 inches (5 cm) long, evergreen with wedge-shaped bases

Scientific Classification of Crown of thorns

Phylum

Vascular plants

Class

Dicotyledons

Order

Nances, spurges, willows and allies

Family

Spurge

Genus

Spurges

Species

Crown of thorns

Planting and Growing of Crown of thorns

Care Difficulty

Easy

Watering Schedule

Every 2 days

Sunlight Requirements

Full sun

Sunshine Duration

4-6 hours

Ideal Temperature

65-75℉

Soil Type

Potting Mix, Peat Mix

Soil pH

6.5-7.5

Fertilizer Type

Balanced

Pruning Season

Spring, Summer

Pruning Area

Branches, Leaves

Pruning Frequency

2 times a year

Repotting Season

Spring

Pot Type

Plastic, Ceramic

How to Water Crown of thorns?

Euphorbia milii, also known as the Crown of Thorns, prefers to dry out slightly between waterings. Water thoroughly, ensuring that around 250 milliliters saturates the soil completely but does not leave it soggy. Aim to moisten the root zone without leaving excess water at the bottom of the pot.

What are the symptoms of an underwatered Crown of thorns? ›

What should I do if my Crown of thorns is not getting enough water? ›

What are the symptoms of an overwatered Crown of thorns? ›

How to save an overwatered Crown of thorns? ›

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What Are the Sunlight Requirements for Crown of thorns?

Sunlight Requirements: Full sun, Partial sun

Duration of light: 4 to 6 hours

Full sun to partial sun exposure is ideal for Euphorbia milii. This range supports vigorous growth and enhances blooming. Adequate sunlight leads to stronger plants with enhanced resistance to diseases.

How much sunlight does Euphorbia milii need? ›

What if the plant gets too little sunlight? ›

How can optimal sunlight exposure benefit the plant? ›

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What Is the Ideal Temperature Range for Crown of thorns?

Ideal Temperature: 65 ~ 75℉

What is the ideal temperature range for growing Euphorbia milii? The ideal temperature range for Euphorbia milii is between 65°F and 75°F. Within this range, the plant can thrive and exhibit optimal growth and blooming conditions. This temperature range mimics the plant's native environment, which is warm but not excessively hot, providing the necessary conditions for both its metabolic processes and flowering cycles.

What Soil is Best for Crown of thorns?

Soil type: Sandy soil, Loam, Sandy loam

Soil PH: 6.5 ~ 7.5

Euphorbia milii thrives in well-drained soil, which prevents waterlogging and root rot. Proper drainage ensures that the roots receive adequate oxygen and nutrients, promoting healthy growth and vibrant blooms. While not overly demanding, Crown of Thorns benefits from a nutrient-rich substrate. This allows it to draw essential minerals over time, supporting vigorous growth and resistance to disease. Excessive fertility can be detrimental, causing leggy growth and fewer flowers. A moderately fertile soil keeps growth compact and encourages more prolific flowering, aligning with the plant's natural growing conditions. More About Soil Group→

How to Fertilize Crown of thorns?

Fertilizer type: Balanced

For Euphorbia milii, it is crucial to apply fertilizer sparingly. Use a balanced liquid fertilizer diluted to half strength, approximately 1/4 teaspoon per gallon of water. For slow-release fertilizers, sprinkle a small handful around the base of the plant once a year, ensuring not to touch the stems directly.

How to Prune Crown of thorns?

Pruning Time: Spring, Summer, Autumn, Winter

Begin by identifying the branches that require pruning. Look for any dead, damaged, or diseased branches as these should be removed first. Prune back any excessively long branches to maintain the desired shape of the plant, encouraging bushier growth and improved airflow. Use sharp, sterilized pruning shears to make clean cuts just above a leaf node or branching point. This encourages the plant to heal quickly and reduces the likelihood of introducing diseases. Clean cuts also help the plant focus its energy on healthy new growth rather than repairing jagged cuts. Once you've finished pruning, collect all removed branches and leaves. Dispose of them carefully, especially if they are diseased, to prevent any potential re-infestation or disease spread in your garden. Consider composting pruned material if it's healthy and free from pests.

How to Propagate Crown of thorns plant?

Propagate Time: Spring, Early summer

Select healthy, non-flowering stems of about 4 to 6 inches long. Use sharp pruning shears to make a clean cut just below a leaf node. Remove any leaves from the lower half of the cutting to minimize water loss.

Allow the cuttings to dry for a few days to form a callus. Plant them into a prepared pot with sterilized potting mix, ensuring they are upright and stable. Water lightly to moisten the soil.

Select healthy seeds and sow them thinly on the surface of a moist potting mix. Cover the seeds lightly with additional potting mix and maintain consistent moisture until germination occurs.

How to Repot Crown of thorns plant?

Repotting frequency: Every 2-3 years

Repot Euphorbia milii when you notice roots growing through drainage holes or when the plant becomes root-bound. The best time is during active growth in spring or summer to minimize stress.

Select a pot with drainage holes to prevent water accumulation. A slightly larger pot than the current one will suffice. This ensures healthy root growth without overwhelming the plant with excess soil.

Opt for a well-draining cactus sole to mimic the plant's natural environment. This prevents water retention, reducing the risk of root rot and ensuring your Euphorbia milii thrives.

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Toxicity of Crown of thorns

Is Crown of thorns toxic to humans?

Despite being a favored houseplant, the crown of thorns is highly toxic, with the ingestion of any part leading to moderate toxicity. The sap of this plant contains harmful substances that can result in irritation to both the eyes and skin if not handled carefully. Exposure to the eyes may lead to swelling and puffiness, while contact with the skin is likely to result in dermatitis. Ingesting any part of the plant can lead to mouth and throat irritation, blistering, vomiting, and abdominal pain. Ingestion of the sap may even cause temporary blindness. Poisoning incidents primarily arise in children, drawn in by the crown of thorns' bright and appealing flowers.

Is Crown of thorns toxic to cat?

The crown of thorns presents a danger of toxicity to felines. If cats inadvertently consume any portion of the plant, they may suffer from poisoning. Contact with crown of thorns can result in a variety of troubling symptoms, such as gastrointestinal disturbances, vomiting, and excessive drooling. Given these possible signs of distress, it is essential to promptly seek veterinary assistance if there is any suspicion that a cat has ingested crown of thorns. Timely and expert care is crucial for addressing any adverse reactions linked to the toxic nature of this plant.

Is Crown of thorns toxic to dog?

The crown of thorns is recognized as toxic to dogs. If dogs happen to ingest any component of the crown of thorns, they face the risk of poisoning due to the plant's toxic nature. Every part of the plant, encompassing leaves, stems, and flowers, harbors harmful substances that can induce detrimental health effects in dogs. Signs of poisoning in dogs may manifest as vomiting, diarrhea, excessive drooling, or more serious symptoms such as lethargy and abdominal discomfort. It is essential for dog owners to remain alert and prevent their pets from accessing crown of thorns. Should a dog consume any part of this plant, it is vital to obtain prompt veterinary assistance to ensure the best possible outcome for the affected animal.

WARNING

The judgment on toxicity and danger is for reference only. We DO NOT GUARANTEE any accuracy of such judgment. Therefore, you SHALL NOT rely on such judgment. It is IMPORTANT TO SEEK PROFESSIONAL ADVICE in advance when necessary.

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