Ascot Rainbow Euphorbia

Ascot Rainbow Euphorbia (Euphorbia x martinii 'Ascot Rainbow') is grown for its leaves rather than its flowers. Every narrow leaf is edged cream over grey green, and in cold weather the tips flush pink and red, so the plant changes through the year without ever losing its shape. It forms a tidy dome about 50cm tall and 60cm wide, then throws lime and yellow flower heads in late winter and spring.

Why you'll love it

• Colour in every season. Cream and green variegation year round, red and pink tips in the cold months, lime flower heads in late winter.
• It thrives on neglect. Drought tolerant, happy in poor soil and salt tolerant, so a dry bank or a coastal verge suits it.
• Frost hardy. Cold southern winters bring out the best colour rather than damaging the plant.
• Neat without work. A self supporting dome at 50cm by 60cm, so there is no staking, no flopping and no shaping.

Where it works best

Borders and edging. Plant 50cm apart for a continuous band of foliage. At that spacing the domes touch without crowding, and the line stays crisp.

Rockeries and dry banks. Sharp drainage and poor soil are what it wants, which makes it one of the few colourful plants for a hot rocky slope.

Pots and small gardens. A 300mm pot holds one comfortably. In a courtyard it gives structure and colour in a footprint smaller than most shrubs.

Growing Ascot Rainbow Euphorbia in Australia

Position and climate. Full sun, always. Shade makes it stretch and dulls the variegation. It suits cool temperate, warm temperate, Mediterranean and arid gardens. It is not a plant for the wet tropics or humid subtropical summers, where the crown rots in warm wet soil.

Soil. Sharp drainage matters more than fertility. Poor, gravelly or sandy soil is ideal. On clay, plant on a raised mound and mix coarse grit through the backfill.

Water and feed. Water weekly through the first summer only, then leave it to the weather. It needs almost no fertiliser, and rich feeding produces soft growth that loses colour.

Pruning. Cut spent flower stems back to the base once the heads brown off, which keeps the dome tight and encourages fresh shoots. Wear gloves and eye protection, because the milky sap irritates skin and eyes.

What to expect when it arrives

This euphorbia comes in two sizes, both multipacks: 140mm pots in packs of ten and 200mm pots in packs of six. That suits the way it is used, since a border or rockery wants numbers rather than one specimen. The 140mm plants establish fast in free draining soil, and the 200mm plants are close to their finished shape.

Stems can bend in transit and the odd broken one is normal. Snap points seal themselves, so trim cleanly and keep the sap off your skin. Plant within a few days, water in once, and expect the dome to fill out over a single warm season. Delivered Australia wide, with delivery from $29.95. Every plant is covered by our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse plants suited to rockeries
• What every gardener should know about variegated plants
• More drought tolerant plants
• Plants for a hot full sun position

Common questions

How far apart should I plant it?

Fifty centimetres apart for a mass planting or a border band. Each plant spreads to about 60cm, so that spacing lets the domes just meet without losing their individual shape.

Is the sap dangerous?

The milky sap is a genuine skin and eye irritant, and it is toxic to cats and dogs if eaten. Wear gloves when cutting, wash your hands afterwards, and keep it out of reach of pets that chew plants.

Will it grow in a humid subtropical garden?

It is a poor choice there. Warm wet summers cause crown and root rot, and the colour fades. It performs best in cool temperate, Mediterranean and dry inland gardens.