Crown of Thorns (Euphorbia milii)

If you‘re looking for an evergreen terrarium succulent to add a bit of dramatic flair to your terrarium, a Crown of Thorns plant may be just the thing for you.

These spiky beauties pack an impressive punch, with their dramatic foliage and vibrant flowers.

In this article, we‘ll take a look at the benefits of adding a Crown of Thorns to your terrarium, as well as care tips to help you keep your succulent healthy and happy.

Quick Stats:
Scientific Name Euphorbia milii
Common Name Crown of Thorns, Christ Thorn
Family Name Euphorbiaceae
Habitat Arid, Subtropical Regions
Temperature 80°F to 85°F
Height 0.5 to 3 feet
pH 6.0 to 8.0
Lighting Partial sunlight

What is Crown of Thorns?

Euphorbia milii is a species of succulent within the spurge family, and it’s native to arid and subtropical regions of Madagascar, South Asia, Southeast Asia, and the Middle East.

This low-maintenance plant is often used as a houseplant or for container gardens and has become a popular accent addition in smaller vivariums.

Euphorbia milii "Crown of Thorns" Care Guide | Terrarium Succulents

Crown of Thorns Facts

Euphorbia milii is also known as the crown of thorns due to the spiky foliage.

This plant can form thick mats, stretching outwards up to one meter in length.

Its thick stems are light green and branch off from reddish, baby leaves and the plant is dotted with small thorns.

Its most notable feature is the bright pink or red flowers, which bloom multiple times a year.


The crown of thorns is a succulent with a unique structure. It is a shallow-rooted plant with branching stems that contain sharp thorns.

The foliage of the Crown of Thorns is typically shades of light greens with occasional branches of pink or red from new leaves.

It is also covered with dot-like thorns all over which can vary in size and shape.

The plant produces flowers that either have a pink or red hue with yellow centers.


The crown of thorns is commonly found in tropical, arid, and subtropical regions.

It is native to Madagascar, South Asia, Southeast Asia, and the Middle East, but it has been introduced to many other countries around the world due to its popularity in container gardens.

pH Preference

The crown of thorns prefers an alkaline pH range, usually between 6.0 and 8.0.

When growing in a vivarium, hobbyists should aim for a constant pH of around 7.5 for optimal growth and flowering.

Vivarium Type

The crown of thorns is quite an easy-going species.

With that in mind, it will not be too complicated when it comes to choosing the type of enclosure it is grown in.

It is best to try and replicate the plant’s natural habitat as much as possible.

Doing so will make it easier to provide this succulent plant with its basic needs.

The proper setup and theme of the enclosure will make a big difference to the overall look and health of the plant. Here are recommended vivariums it will do well in:

    • Paludariums – Half aquatic/ half terrain-based enclosure.

    • Terrariums – Fully terrain-based enclosures with little to no aquatic features.

Vivarium Placement

Euphorbia milii is best suited for smaller vivariums where it can be placed as a centerpiece.

The plant likes to be slightly elevated, so hobbyists can place it on a couple of small terracotta stones or low rocks.


The crown of thorns should be planted in well-drained soil or another terrarium substrate for optimal growth.

A soil with a good balance of nutrients, such as pumice, perlite, and vermiculite, is ideal. This type of soil helps absorb water and nutrients and helps keep the soil lightly moist.


The crown of thorns prefers partial sunlight and should be placed in an area of the vivarium that gets some direct light.

A full-spectrum LED bulb is the best choice for providing a balanced amount of light.

Depending on the season, hobbyists should adjust the light cycle to ensure the plant receives enough terrarium lighting.

Buy Crown of Thorns

When it comes to buying a crown of thorns plant, there are a few things to keep in mind.

Making sure the plant is healthy when purchased is essential for its success in a vivarium.

Vegetation that is already in poor conditions will have a very hard time adjusting to new environments.

Click the image below to find out more about the current price and other relative info about this plant.

Crown of Thorns Care and Propagation

Thanks to its low-maintenance and resilient nature, the crown of thorns is relatively easy to care for and propagate.

For propagation, simply break off baby stems from the main plant, with each one having at least one leaf or baby branch and the root node.

Plant the cut pieces into dry, well-drained soil or other substrate and give the plants ample sunlight and moderate watering. 


The crown of thorns does not need a lot of water and should only be watered when the soil is dry to the touch.

Too much water can cause the plant to rot, so it is important to make sure the soil is not overly wet.

A general rule of thumb is to water the plant every two to three weeks.

Plants Similar to Crown of Thorns

Adding diversity to an enclosure is key to an aesthetically pleasing setup.

Try mixing up the look of your vivarium with different flora that can easily co-exist in the same environment.

Furthermore, if for some reason you find the crown of thorns hard to acquire or would like to consider something similar to this plant…

Here are other succulents you might find will do well with or in the place of Euphorbia milii:

Sempervivum tectorum "Hens and Chicks" Terrarium Care Guide
Sedum Spp. "Stonecrop" Care Guide | Terrarium Succulents
Kalanchoe tomentosa "Panda Plant" Care Guide | Terrarium Succulents


Overall, the crown of thorns is a great terrarium plant to add to your vivarium. The plant is fairly low-maintenance and its bright flowers add a burst of color to any enclosure.

However, it is important to remember that this plant is a succulent and needs to be watered sparingly.

With the proper care, Euphorbia milii will thrive in any vivarium, adding texture and color to your setup.

Frequently Asked Questions

Crown of thorns (Euphorbia milii) is considered to be highly toxic and can cause skin irritation, nausea, vomiting, and diarrhea if ingested. The sap of the plant contains a toxin called euphorbon which can cause severe irritation and burning of the skin, eyes, and mucous membranes. The plant is also known to be toxic to animals if ingested.

Yes, Euphorbia milii, commonly known as the Crown of Thorns Plant, is an easytocarefor, droughttolerant indoor plant. This tropical succulent is a great choice if you‘re looking for a lowmaintenance addition to your home or terrarium.

Euphorbia milii, commonly known as Crown of Thorns, typically grows from 0.5 to 3 feet (1590 cm) in height.

No, crown of thorns is an evergreen plant that produces bright red, starshaped flowers throughout the year in warm climates, but blooms mainly in the spring and summer.

Crown of thorns prefer bright sunlight for optimal growth and blooming, but can tolerate some shade.

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