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Euphorbia milii (Crown of thorns): Growth And Care Guide

The crown of thorns plant goes by many names. Its main name is the Euphorbia milii but is also called christ thorn or christ plant.  It is a succulent with bright green, thick foliage, and green blooms.

Euphorbia milii (Crown of thorns): All you need to know about its growth and care

Its most distinguishing features are its long stems. These stems are riddled with tiny thorns. Another cool feature is its flowers being surrounded by colorful bracts. The thorns also produce a sticky liquid when touched.

This Euphorbia variety is a popular houseplant that can also be grown outdoors. It has a slow growth rate and belongs to the Euphorbiaceae family. You can find the crown of thorn plants growing in tropical regions of Africa like Madagascar.

It is poisonous to both people and pets when touched or ingested. So be cautious when dealing with or handling them.  

Botanical NameEuphorbia milii 
Common NamesCrown of thorns, christ plant, Christ thorn. 
Plant TypeSucculent herbaceous perennial 
Full SizeRanges from 2 feet to 6 feet tall
Sun ExposureFull or direct sunlight to partial shade
Soil TypeWell-draining soil
ToxicityToxic to both pets and people

Crown of Thorns Plant Care

The thorn crown plant is an average-maintenance plant. It does have simple growth requirements. But its small thorns might make handling a bit difficult. Also, its poisonous sap is a reason protective gloves would be needed. 

Crown of Thorns Plant Care
World of Succulents

Crown of Thorns light requirements 

Euphorbia milii is a flowering plant. As such, it would need a lot of direct sunlight to produce proper blooms. This is why they do well with at least 4 hours of sunlight each day. They can also grow in areas of filtered sunlight. But ensure the light intensity is bright. 

Too little sunlight would lead to stunted plant growth. It would produce poor flowers and its leaves would appear darker green. 

Place the potted plant in a room next to the west or south-facing window. During the winter, you can consider using artificial sunlight indoors. 

Crown of Thorns Watering Requirements 

The Crown of thorns bush can survive some level of neglect. This is because it is a succulent that can store water for long periods. Still do not underwater it as this can cause the plant to dry up. 

Also, avoid overwatering the plant. Its roots don’t do well when sitting in soggy soil.  They are more susceptible to fungi attacks like root rot. This is because of the excess moisture caused by overwatering. 

Aim for moist soil. You can do this by letting the topmost part of the soil dry before watering. Using a moisture meter can help with better watering. A cheaper option would be to feel the soil with your fingers. If it feels a little dry, then proceed to watering. 

It would need less watering during the winter season. This is because the crown plant goes dormant during this period. Also, use rainwater and avoid tap water. They contain chlorine, which is harmful to the plant. 

Crown of Thorns Soil Requirements  

Crown of Thorns Soil Requirements  

First, ensure you get a pot with enough drainage holes. This is because the plant does well in well-draining soil.  You can decide to purchase a cactus mix at a store. 

A cheaper option would be to make your own mix. This can be done with regular potting soil. Add some perlite and peat moss to create a suitable mix. 

It should range between a little acidic and neutral. So, keep the pH between the values 6. 5 to 7.0.

Crown of Thorns Humidity and Temperature Requirements 

Temperature levels should be kept moderate. A range from 50 degrees Fahrenheit to 75 degrees Fahrenheit is okay. But do not let it go below 50 degrees Fahrenheit as the plant isn’t cold or frost hardy.

They can survive moderate humidity. A level between 40% to 60% is an appropriate humidity level.  You can achieve this with regular misting. Or you can purchase and make use of a humidifier. 

Crown of Thorns Fertilizer Requirements 

Frequent fertilizer feeding is not recommended. But you should fertilize the exotic plant during its growing season. For this, use a well-balanced liquid soluble fertilizer. This fertilizer should be diluted by at least 50% before use. 

Crown of Thorns Plant Propagation and Pruning

Crown of Thorns Plant Propagation and Pruning
Plant Care & Propagation

Propagating the crown of thorns can be done through cuttings. Sterilize the tools before use and ensure you wear protective gloves.

Pruning would be required to keep the plant fresh. You also promote healthy leaf growth with regular pruning. Be careful when doing this and ensure you don’t injure the plant. 

Common Health Problems of Euphorbia Milii

  • Root rot
  • Yellow leaves
  • Botrytis
  • Mealybugs
  • Scales 
  • Thrips

Frequently Asked Questions

Where can I buy a crown of thorns plant?

They can be purchased in most online stores like Amazon. You can also purchase them from walk-in plant stores.

What other plant has thorns?  

Plants like the Natal plum, Holly, or Silverthorn, all possess thorns. 

Is the Crown of thorns plant fast-growing?

No, they have a rather slow growth rate.

How long does it take a crown of thorns to bloom?

It takes several weeks as they produce blooms in the spring season.

Do crowns of thorns like to be root bound?

Because of their slow growth. They can live in pots for longer periods without needing change.