Crown Of Thorns – Euphorbia milii

Originally from Madagascar, this surprising plant with its fleshy leaves, sharp thorns and bright red flower bracts, was once thought to have formed the Crown of Thorns which Jesus wore.

Widely available and easy to look after, the Crown of Thorns has amazing powers of recuperation if neglected, and with a little care it can be encouraged to flower all year round. Beware of the sharp spikes and the sap, which is an irritant, and in some species, poisonous. Wash it off your skin immediately and take care not to get it into cuts. Put the plants where they can’t be touched by children or easily knocked over.

The Crown of Thorns can be bought as a smallish house plant, but over the years it can develop into a 90cm (3ft) bush. However, annual pruning will keep it to a sensible size and give you lots of cuttings to make new plants.Crown Of Thorns - Euphorbia milii

There are several types of Crown of Thorns available. These include Em hisloppii which has red or pink bracks and 25mm (1 in) long thorns mounted on 5-6cm (2-2.5in) stems. Another, Em splendeus, grows to 1.8 (oft) with 1.5cm (3/4in) stems.


Your Crown of Thorns can live for many years and will go on growing every year. If allowed to, it can get quite large and bushy. So, in March or April prune your plant and use the prunings as cuttings.

1 Take stem cuttings about 8cm (3in) long. Dip the cuttings into water to stop sap flow then let the cuttings dry out for 24 hours before potting. Remember to avoid getting any sap on your skin — it is an irritant and can be poisonous.

2 Use a good cactus compost or one made of a mixture of equal parts loam, peat and sand. The compost should be just moist, not wet. The upper two thirds of the compost mixture should be allowed to become dry between waterings.

3 Put three or four cuttings in a pot. Place the pots over a heat source, such as a radiator, at around 22°-26°C (72°-77°F). Avoid exposing the cuttings to direct sunlight for the first four or five weeks as this inhibits good root formation. Within 5 to 8 weeks the cuttings should have rooted so put in pots containing soil-based potting compost.

Plant Problems

Leaves turning yellow and falling off may be due to very dry root conditions, especially in winter. Treatment: Do not let the roots dry out completely.

Leaves turning brown at the tips may indicate crown or root rot, caused by over watering. Treatment: Allow soil to dry out and then water only when the soil is dry on top.

Grey-brown dead areas on leaves indicate scale insect infestation. Treatment: Wipe off the brown shells with damp cotton wool and treat the plant with insecticide.


The Crown of Thorns does not need the daily nursing of many less exotic plants and is able to withstand quite a lot of neglect. Pruning each year will be needed to keep the bush to a reasonable size. After pruning, stop the sap flow at once with a waterspray.

  • Potting: Use either equal amounts of loam, peat and sand or a cactus compost when you repot it every two years.
  • Water moderately from spring and through the summer. In winter, water sparingly. Do not let the surface of the soil stay wet, but let it dry between waterings.
  • Feeding: Feed every couple of weeks in the summer.


Light: The Crown of Thorns needs to be sitting on a sunny window with lots of good light, or in the greenhouse. In fact, the stronger the sun, the longer its period of flowering.

Temperature: Normal room temperatures will suit these heat-loving plants. They like central heating and need minimum temperatures of around 55°F (13°C).

When to buy

  • All year round from garden centres and shops.
  • Choose a plant which is bushy and sturdy with some flowers and lots of developing bracts.
  • Crown of Thorns is a perennial which can live for years and grow into a large-sized plant.

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