Crown of Thorns

Crown of Thorns (Euphorbia milii) flowers for most of the year on almost no water. It forms a low woody mound to about 1m tall and 0.8m wide, with red and pink bracts held above thick spined stems, and it keeps going through heat that stops other flowering shrubs. If you have a hot, dry, poor soil spot that has defeated everything else, try this there.

Why you'll love it

• Colour nearly all year. In warm gardens the bracts keep coming through spring, summer and autumn, pausing only in the coolest weeks.
• Genuinely drought tolerant. Thick succulent stems store their own water, so it survives long dry spells and looks better for the neglect.
• Poor soil is fine. Sand, gravel, thin rocky ground and reflected heat off a wall are all within range, and it is salt tolerant.
• Small and containable. At 1m by 0.8m it fits a pot, a rockery pocket or a border without ever needing hard cutting back. No staking, no spraying, and a shape up in spring is the whole job.

Where it works best

Pots and containers. A 300mm to 400mm pot of free draining cactus and succulent mix suits it, and a pot lets you move it under shelter in winter or out of reach in a family garden.

Rockeries and hot dry beds. Between rocks, on a slope, or along a west facing wall where the soil bakes and little else flowers.

Borders and edging. Plant about 60cm apart for a low run of colour along a path or driveway. Set it just off the edge rather than overhanging it, because of the spines.

Growing Crown of Thorns in Australia

Position and climate. Full sun, six hours a day minimum, since flowering falls away sharply in shade. It suits tropical, subtropical, warm temperate and arid or semi arid gardens. Being frost tender, it is a pot plant in cool temperate and frosty inland gardens, moved under eaves for winter.

Soil. Sharp drainage is the one thing it insists on: sandy or gritty soil in the ground, a cactus mix in pots. Heavy wet soil over winter is what kills these plants, not cold or drought.

Water and feed. In summer, water only when the top 5cm is dry. Through winter, next to nothing. A light dose of succulent fertiliser in spring and midsummer is plenty, because rich feeding gives soft leafy growth and fewer flowers.

Pruning and handling. Shape it in spring, taking stems back to a junction. Wear gloves and eye protection: the stems carry sharp spines, and the milky sap irritates skin and eyes and is toxic if eaten.

What to expect when it arrives

It is supplied as a 200mm pack of six, the right quantity for a border run, a rockery group or matched pots. Plants arrive as established young shrubs with several branched stems and, in the warm months, often some colour showing. Handle them by the pot rim, not the stems.

Plants are packed to travel upright and delivered Australia wide, with delivery from $29.95. Advanced and large stock is freighted at cost. Expect them to sit quietly for a fortnight, then push new growth. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse the full succulent range
• Drought tolerant plants for dry gardens
• Plants that perform in containers
• Getting drainage right before you plant

Common questions

Is it toxic?

Yes. The milky sap is a skin and eye irritant and is poisonous if swallowed, and the stems carry sharp spines. Keep it away from areas used by small children and pets, and wear gloves when pruning or repotting.

Why has it stopped flowering?

Almost always too little sun or too much water. Move it into full sun, water only when the soil is dry, and hold off the fertiliser. Flowering usually returns within a few weeks in warm weather.

Can I grow it indoors?

Only in the brightest spot you have, against a north facing window. In lower light it stretches and stops flowering. A sunny balcony or covered patio is a better winter home.