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Crown of Thorns (Euphorbia milii) Plant Care 101

As a desert succulent originating from the island of Madagascar, the Crown of Thorns (Euphorbia milii) is a member of the Spurge family, or Euphorbiaceae.

Plants in this family, like the Crown of Thorns, are grouped together for their fleshy green leaves, and small flowers that grow in clusters. Being highly adaptable, these plants are ideal candidates for those wanting an indoor collectible. 

Flowering houseplants are typically tricky in terms of their care. They require careful attention to certain factors such as watering, temperature, humidity, and repotting. Fortunately, those with a Crown of Thorns in their home need not worry.

Crown of Thorns Plant Care Guide 



Succulents are commonly known for their easy-to-please nature in regards to indoor care. Even so, you should still be aware of the different needs involving keeping your Crown of Thorns alive.

The following lists all of their general requirements meant for daily care.



Soil requirements aren’t all that strenuous. The main preference that they have is for the soil to be well draining, sandy, and mixed with organic material such as humus.

Taking note of which soil you purchase will greatly impact your Crown of Thorns. These plants do not thrive when placed in a pot with the average commercial product. 



There are several succulents that prefer to be placed in an area with direct sunlight. This Euphorbia is a more sensitive individual, needing plenty of light, though not for as long as one would expect.

They do like to be placed in direct sunlight, but this will cause the flowers to fade in color. Instead, your plant would do best when given lots of indirect, bright light. 



The first rule of watering your Crown of Thorns is to include a good amount of drainage holes on the bottom of the pot. The needs for these plants are relatively low for a flowering plant.

This depends on the temperature that you place your Crown of Thorns in. In a warmer room, you should provide more moisture, being careful to not overwater. A good tip is to feel the inch below the soil’s surface. If it is dry, then it needs a thorough watering.



Preferring warmer temperatures, the Crown of Thorns plant is tolerant to a wide range. Even if your house gets to about 26 degrees Celsius, this Euphorbia won’t be critically impacted.

In fact, they can survive any temperature, as long as it does not exceed below 2 Degrees Celsius. This is only short a short period, though, as the leaves will start to fall off. An indoor Crown of Thorns plants should be kept right around 12 degrees Celsius for the best results. 



Being a succulent, this Euphorbiaceae member is more particular about the temperature requirements. Their humidity needs are relatively low, preferring a drier living condition.

This makes them highly coveted by those with indoor plants. The Crown of Thorns does not need any additional misting, making your job all that much easier. 


The Crown of Thorns plant is a fairly consistent to bloom, producing large, vibrant flowers when they do. Adding a fertilizer will do no harm to the plant as long as you keep the season in mind.

When these plants are first planted, they’ll need all the help they can get. Most choose to give them an undiluted solution during this time. After that, fertilizer can be added during the warmer months at half the recommended dose.

Regular fertilizer use should be about once a month. 


You may not know this, but Euphorbia milii is a long-lasting flowering succulent, sometimes known to last up to 50 years. This rings true for those who choose to keep these plants indoors.

Propagating your Crown of Thorns may be beneficial if you have a beloved Euphorb that is exceptionally talented at producing large flowers.

These plants can be propagated through several methods such as stem cuttings, in water, and through seed germination. Out of all these techniques, cuttings seem to be the most commonly used. 



These plants are known for being slow to grow to their full height, which are about 3 feet tall and 2 feet wide. When living in outdoor settings, they tend to stretch out a little more, sometimes even being a staggering 6 feet in height.

The reason for this slower growth is largely due to their large flowers. It takes a lot of energy to bloom as regularly as the Crown of Thorns does. 



Although these are considered to a flowering species, the act of repotting doesn’t all in line with this category. The fact that they don’t grow quickly means that you should likely repot them every few years.

They aren’t known for getting root bound either, so owners don’t need to worry about them becoming cramped in their living space. 



On par with most succulents, the Crown of Thorns plant only has a few recommendations when it comes to a regular watering schedule. You may accidentally forget to water this Euphorbia. In those cases, it’s easy to nurture back to life.

The following section will tell you how much water to add, how often, and any tricks that have helped others. 



Let’s first look at how frequent your watering schedule should be for this flowering succulent. A useful tidbit of knowledge may help you understand why they don’t need a lot of water to begin with.

The leaves of the Crown of Thorns are fleshy. That paired with thick stems helps it to store water whenever a drought presents itself, just as if it still lived in the desert.

You can expect to water this type of plant once a week, at the very most. There is an exception, but less common for indoor plants. Those with a warmer house should provide their Crown of Thorns plant with a more frequent watering schedule.

Still watch out for overwatering, as this plant does not do well with too much moisture. 

Curious about how much water should be added? There’s an easy trick to determine just that. To avoid the risk of root rotting, you’ll want to feel the soil about an inch underneath the top layer.

If it is dried out, then the plant can be thoroughly watered, letting the excess moisture drain out the bottom of the pot. Always allow plenty of time between watering sessions. 



As stated above, propagation is most easily executed through the method of stem cuttings. If you want to make a copy from your current individual, opt to make cuttings during the warmer months.

This will give them time to grow with plenty of sunshine. Please keep in mind that the sap produced by these plants irritates the skin and eyes. Wearing gloves and goggles will limit the chance of this happening. 

The following steps can aid in propagating these plants in a stress-free method. 



  1. Decide which individual you would want to copy, preferably one with successful blooms throughout the year.
  2. Taking a clean pair of scissors, make a two to four inch cut on an older stem. Be sure to keep a few leaves and buds with this cutting. 
  3. Once you have your cutting, run it under cold water and place to the side for a few days. Having the stem dry out before placing it into soil will decrease the chance of developing root rot. 
  4. Place your dried out stem cutting into a pot with fresh, slightly sandy soil, being sure that it is at least two inches deep. 
  5. Drizzle the soil with water, letting it dry out before adding more. Set your new cutting in a window that gets plenty of warm, indirect sunlight. 
  6. Check back every so often. Roots should form around two weeks after it has been potted. Once this happens, you can transfer it to a new container. 



The Crown of Thorns plant is considered an evergreen shrub, sometimes growing unruly. It takes them a while to get to this point, usually needing to be trimmed back after the second or third year. 

One important thing to note is that these plants are considered toxic. If you were to rub your eyes after handling the prickly stems, you would experience a good amount of irritation. 

As for the pruning process itself, it isn’t necessarily a requirement. If you do not like the look of a bushy houseplant, you can take off a few stems.

The best method is to make your incisions at the base of the stem, so that it won’t grow back in a stubby fashion. At this time, you can also remove any dying or dead growth. This will preserve the overall health of your Crown of Thorns plant. 



As many plant owners know, there are several conditions and diseases that can affect the growth and wellbeing of your indoor collection.

We’ve taken the liberty to highlight two of the most common problems that affect these plants, as well as some ways that you can help reduce further damage. 




Cause: The yellowing of leaves in combination with them falling off the branch can be a number of factors. The two most regular causes are either over-watering, or a cold draft.  

Remedy: Trying to rule out which problem your plant is experiencing should be the first step. Taking a step back from watering can quickly allow you to see if the leaves are turning yellow due to excessive moisture. If no change happens, look into any potential drafts that are in your home. 




Cause: The lower leaves on a Crown of Thorns plant will begin to shrivel up and fall off sometimes because the individual is lacking in either light or moisture. Another potential cause is that your succulent has too much heat.  

Remedy: If your plant is experiencing too much heat, this may also impact the amount of moisture that’s getting down to the roots. Attempt to solve the warmth problem first and go from there. You won’t be able to save the leaves that have already shriveled up, but it will stop future dead foliage. After addressing possible heat issues, move your plant to an area that has less direct light. 



We understand that taking care of plants isn’t always the easiest feat. That is why we have taken the five most important Crown of Thorns care instructions and placed them into a checklist for you to reference. 

  1. Make a point to keep your home within a temperature range of about 12 to 26 degrees Celsius. Any lower can lead to negative affects. 
  2. Choose a spot that gets plenty of warmth and indirect sunlight. They can handle direct light, but these conditions will eventually cause the pigmentation in the flowers to fade. 
  3. Unless you have an exceptionally warm house, only water your Crown of Thorns when it is absolutely necessary, typically a little over a week. 
  4. Implement fertilizer in the warmer months to promote healthy blooms. 
  5. Begin pruning back your Euphorbia after two years of growth, always taking extra precautions with gloves and goggles if you’re worried about irritation. 




How do you get a Crown of Thorns plant to bloom?

Following the bare needs is a great start to allowing plentiful blooms. Other tips include the use fertilizer as well as regular pruning. 


What colors does a Crown of Thorns come in?

Known for their large flowers, they vary greatly in color. They can range vary between red, yellow, white, and pink colors. There are even specially modified hybrids that have larger and flashier flowers. 


Where does the Crown of Thorns plant name come from?

This prickly, beautiful succulent was named to symbolize the crown that Jesus Christ wore at the time of his crucifixion. Legends state that the stems belonging to this plant were actually used in that time frame.

Author Bio

Daniel Iseli

Taking care of houseplants and gardening are my greatest passions. I am transforming my apartment into an urban jungle and am growing veggies in my indoor and outdoor garden year-round.