Euphorbia Milii “Crown Of Thorns Plant”

euphorbia milii

Last updated on August 29th, 2022 at 05:07 am

The Euphorbia milii plant, also known as the crown of thorns plant, is a cactus species that can grow to be up to two or three meters tall. The flowers are usually white, pink, and yellow in coloration with a range of hues. They bloom only once every five years making them an extremely rare sight for those observing their natural habitat.

Crowns of thorn plants thrive in the drier regions of sub-Saharan Africa. Their natural habitat is found on top of hills and mountains, dry river beds, dunes, and deserts. This means that they are not suited for a temperate climate so it’s important to provide them with plenty of bright sunlight especially during winter months when nights grow longer and days grow shorter.

Other than the fact that they are a cactus species, there is not much known about their natural habitat because it’s such an inhospitable environment which makes it uncommon for visitors to see these plants at their natural home.

Euphorbia milii propagation

euphorbia milii

The propagation of the Euphorbia milii plant is a relatively simple process. It’s done through either cuttings or seeds and both methods have their pros and cons, especially with regards to the time required for successful growth.

Cutting off portions from an existing cactus can be difficult if you don’t know what you’re doing. It’s also important to remember that the cutting will take some time before it grows into a new cactus plant.

The other option is to plant a seed and it will grow into a new Euphorbia milii plant in about two years’ time, but this requires the purchase of seeds which can be expensive since they are not mass-produced. If you’re looking for instant gratification, then planting seeds might not be your best bet as this takes about two years for the plant to grow into a new Euphorbia milii cactus.

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Crown of thorns plant care

euphorbia milii

Light requirement

Euphorbia milii plants can grow in a wide variety of lighting conditions. It does best with bright, indirect light or filtered sunlight but will also flourish under medium to high levels of artificial light from an office building window. They don’t do well when they are kept exclusively in the dark for long periods of time or exposed to direct sunlight constantly.

A Euphorbia milii plant that has been grown in bright, indirect sunlight will be more tolerant to direct sun. If you are trying to acclimate it from low-light conditions, the most effective way is by shielding it with other plants or green foliage on sunny days. This allows for a gradual adjustment so they can get used to the change in conditions.

Soil/poting mix

Euphorbia milii plants are native to semi-arid areas. They require a very well drained soil so that the roots don’t rot from being constantly moist and sitting in water all day long.

The crowns also thrive on coarse or gritty soil; it needs spaces for air pockets below its root system. If the mix is too clay-heavy, it will make the soil too water-retentive.

Euphorbia miliis can be grown in pots with a cactus mix or potting soil that is high in sand and charcoal for added drainage properties. The crowns are heavy feeders so they require more fertilizer during active growth periods to maintain their health.


euphorbia milii

Euphorbia milii plants require more fertilizer during active growth periods to maintain their health.

The best time for fertilizing is in the springtime when the buds are starting to show themselves or after a large rainstorm. The crown of thorns doesn’t need as much nutrients once they have matured and settled into dormancy, so you can use an organic slow-release fertilizer like Hollytone.

Euphorbia milii plant will need more fertilizers than other plants because they are heavy feeders and their roots can’t reach down very far to gather nutrients from the soil, so it’s important that you provide ample amounts for them. If your plant is not doing well or if its growth slows down considerably, it may be a sign that you need to fertilize more.

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Euphorbia miliis are usually found in semi-arid climates and require plenty of water. The best time to water them is after a deep rain or when the top three inches of soil have dried out, but not so often that they become root-bound.

If you’re giving your plant too much water all at once, it can cause the roots to rot and the crown will begin to droop. When this happens, cut back on how often you water it until it regains its balance.


Euphorbia milii plants can withstand a wide range of temperatures and are not easily damaged by frost. They actually prefer warmer climates with higher humidity levels, but they will also tolerate dryer seasons as long as their soil does not stay constantly moist.

The ideal temperature for crowns of thorns plants is between 25-40 degrees Celsius. The plants need a lot of light and prefer it to be bright, but not scorching hot.


Euphorbia milii plants prefer warmer climates with higher humidity levels. In the drier seasons, make sure that your plant’s soil doesn’t stay constantly moist or it will rot from being constantly watered.

The ideal range for humidity is between 50%-75%.

Growth rate

euphorbia milii

The Euphorbia milii plant is a fairly slow growing houseplant. In the summer, it can grow up to two feet in height and width whereas during winter months, it will be half that size.


Euphorbia milii plants should be repotted every couple of years, or when the plant starts to outgrow its pot.


The Euphorbia milii plant should be pruned every couple years, or when the plant starts to outgrow its pot.


The Euphorbia milii plant is toxic to pets, so keep it away from animals.

Pests and diseases

Euphorbia milii plants are generally resistant to pests and diseases, but can be susceptible in some cases. Euphorbia miliis can suffer from root rot caused by the bacteria Erwinia species or fungal infections such as Armillaria species (mushroom). Symptoms include wilting leaves, yellowing foliage, stunted growth and deformed plant growth.

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Surprisingly, Euphorbia miliis plants are not that susceptible to pests and diseases. The only things you should worry about is if the soil isn’t draining or wet enough, which can lead to root rot. If this happens, it’s best to divide the plants into smaller clumps so they can get better access to oxygen.