Better Know a Houseplant: Euphorbia Milii Splendens

In my first discussion of insecticidal soap I mentioned how it must not be applied to Euphorbia milii splendens, the Crown of Thorns. Mine is currently in bloom for the first time this season, and in this post I introduce this graceful plant and discuss how I care for it - but I might as well cut it short by saying it is very easy to care for. So, if you find yourself intrigued by its spiny stems and striking delicate flowers, go ahead and purchase one, it will definitely add to your plant display.
The Euphorbia milii splendens, commonly known as the Crown of Thorns (legend has it that it was this plant that was used to make a crown of thorns for Jesus Christ at the time of his crucifixion), is a woody succulent plant. Despite the fact that it is a spiny stemmed plant, it is not a cactus. The grey spines cover all of the stem and reach up to three centimeters in length. The leaves are oval in shape and waxy green. Euphorbia will grow tall and will start trailing, or climbing if supported, after reaching a certain length; my parents have a specimen that seems to be trailing all over the place without any apparent extra care, mine is less than 30 cm long and the stems are still shooting upright. If you planting it in a permanent location outside of a container, be careful where you place the plant because, as it grows and starts trailing or climbing, it will do so over any other plants in its way, so don't give it a permanent home closely neighboring any other plants.


I find the contrast between the woody spiny stems and the delicate flowers it produces most fascinating: The flowers are actually quite small and yellow in color, and each is surrounded by a pair of bright red waxy bracts (there are a number of varieties and cultivars of various leaf sizes producing different colors, including white, pink, and yellow - but the red ones are always my favorites).

As to plant care, the plant requires full sunlight; I have had mine placed on the outer edge of a north-facing balcony for many years now, where it receives direct afternoon and sunset light, and it seems to be thriving there. Euphorbia milii does not require much watering, in fact, the soil should be allowed to dry between waterings; it will defoliate under excessive humidity or if receiving too much water, so a tell-tale sign you are probably overwatering your plant is the loss of leaves. Regular spraying is recommended, but be careful not to spray the delicate flower when the plant is in bloom.


As I mentioned at the start of this post, and in the entry about insecticidal soap, the Crown of Thorns must not be treated using soap solutions. I haven't done my homework researching the exact reasons why (I will be updating this post once I do), but when spraying the plant, you will notice the waxiness of the leaf surface, and I guess the soap possibly destroys this layer and disrupts its function.

Last, it is worth mentioning that Euphorbia milii is a poisonous plant: it will exude sticky white sap, called latex, from any cut surface; the latex may irritate the skin it comes in touch with, especially in susceptible persons, and is poisonous when ingested in large quantities.

In all, the Euphorbia milii is a low-maintenance plant; for minimal work you can grow this strikingly beautiful plant. Other varieties to look for are ones with larger leaves, and, as previously mentioned, other color varieties of the bract - again, I think all pale in comparison to the red ones.