How to grow and care for Euphorbias
Ranging from tender cactus-like succulents to long-flowering architectural plants which make a big impact in your garden, the Euphorbia or spurge, belongs to the Euphorbiaceae family, made up of over 2000 species. Hailing from a diverse range of habitats and regions, there’s a Euphorbia to suit you – whether you’re looking for a houseplant, some hardy ground cover or an evergreen shrub.
Types of Euphorbias plants to grow
With many Euphorbia varieties to choose from, here is a selection of the most popular and easy to grow Euphorbia plants, starting with a couple of houseplants and progressing in height to the tallest specimens for the garden.
- Euphorbia pulcherrima: otherwise known as Poinsettia, the red flower-like bracts of which are so popular at Christmas. Originating in Mexico, this euphorbia is happiest as a houseplant or in a conservatory or heated greenhouse.
- Euphorbia milii: the thorny stems of this striking succulent houseplant give it the common name of crown of thorns. It has cup-like scarlet bracts with yellow centres in spring and summer and leathery evergreen leaves.
- Euphorbia cyparissias ‘Fens Ruby’: a feathery-leaved perennial for a sunny position, this fast-growing plant up to 50cm high has greenish yellow flowers and can spread to 1.5m.
- Euphorbia myrsinites: its creeping habit makes it a useful evergreen ground cover plant with overlapping blue-grey leaves on stems up to 35cm long and clusters of lime green flowers.
- Euphorbia Diamond Frost: is a tender perennial Euphorbia which is often grown as an annual for its tiny white flowers like slivers of ice. Useful for containers and hanging baskets.
- Euphorbia amygdaloides var. robbiae: a low-growing Euphorbia plant (to 50cm) with a spreading habit which copes well with dry shade. Greenish yellow flowers rise from dark evergreen rosettes. Euphorbia amygdaloides var. Purpurea has deep purple leaves and stems, lime green flowers and can reach 1m.
- Euphorbia palustris: the marsh spurge prefers to grow in moist soil in full sun. Growing to between 50cm to 1m, it bears clusters of bright yellow-green flowers in late spring.
- Euphorbia griffithii: distinctive for its orange flowers in early summer, this euphorbia plant grows to between 50cm and 1m and dies back over the winter. Euphorbia griffithii Fireglow is another red euphorbia with red-tinged leaves and orange-red flowers.
- Euphorbia x martinii: bearing narrow mid-green leaves and bright lime green bracts with a red eye, this weed-smothering evergreen grows in upright clumps reaching approximately 1m. Euphorbia x martinii Ascot Rainbow has pinkish leaves aging to creamy yellow.
- Euphorbia characias: reaching 1.2m this evergreen euphorbia has striking spherical or cylindrical flowerheads made up of clusters of purple-lined green flowers with bright yellow centres. Euphorbia characias subsp. Wulfenii is similar but without the purple colouring.
- Euphorbia mellifera: the honey spurge is a handsome shrub from Madeira up to 2m tall with brown honey-scented flowers in late spring.
What you’ll need to grow Euphorbias
Euphorbias grow in most types of soil as long as it is fertile and well drained. If your soil is heavy clay, improve drainage by introducing some horticultural grit into the planting hole. For more free-draining soils, add some well-rotted manure to the planting hole to enrich the soil and help to retain nutrients. Smaller forms of Euphorbia can be planted in large containers, using peat-free compost.
Where to plant and place your Euphorbias
Before you buy your Euphorbia plant, check the label carefully to make sure that you have the right location and growing conditions for it to thrive: it’s a case of right place, right plant.
The succulent, silver leaved varieties such as Euphorbia myrsinites like a sunny position in a rockery or in well-drained soil at the front of a border. Choose a sunny location for Euphorbia characias and other euphorbias with grey-green foliage indicating their Mediterranean origin. Woodland spurges such as Euphorbia x martinii, Euphorbia amygdaloides var. robbiae and Euphorbia amygdaloides var. purpurea prefer shadier conditions. Allow plenty of space for the taller growing varieties like Euphorbia mellifera by placing them at the back of a sunny border where they have room to spread and be displayed to best advantage.
Caring and nurturing your Euphorbias
Follow these euphorbia care tips for successful growing:
- Plant in full sun or, for the wood spurge types like Euphorbia amygdaloides, in semi-shade.
- Mulch each year, in early spring, with leaf mould or well-rotted manure.
- Most of the garden type euphorbias can withstand below zero temperatures. Keep house plant varieties such as poinsettias and Euphorbia milii frost free.
- Water well after planting and mulch around the base of the plant to conserve moisture and suppress weeds.
- Euphorbias grow well in all soil types.
- Wear gloves and long sleeves when pruning euphorbias to avoid contact with the milky sap which causes skin irritation. After flowering, deadhead the herbaceous perennials like E. cyparissias, E. griffithii and E. palustris. Cut down Euphorpia characias and Euphorbia myrsinities to ground level after flowering, to encourage fresh re-growth. Cut the flowering shoots of Euphorbia mellifera down to the base of the plant in late summer and autumn.
- Re-pot euphorbias grown in containers every few years in fresh peat free compost.
- Take cuttings of the shrubby forms of euphorbia to increase your stock of these beautiful plants. The new growth that appears after you cut back E. characias, E. mellifera or E. myrsinites makes good material for cuttings. Cut pieces that are between 3cm to 6cm long, trim off lower leaves and plant into 7cm pots of peat free seed and potting compost, 3 per pot. Once the cuttings have rooted, pot them up into 10cm pots. Euphorbias self-seed and it’s a good idea to pot up some of these seedlings to grow on to plant elsewhere in the garden or to give away. You can divide the herbaceous euphorbias such as E. cyparissias ‘Fens Ruby’, E. griffithii or E. palustris to make new plants, lifting the plant from the soil and teasing out the individual plants and planting them into 10cm pots and replacing the main plant into the soil.
Key features of Euphorbias
Botanical Name: Euphorbia species.
Plant Type: Shrubs or herbaceous perennials
Light Exposure: Usually prefer full or partial sun.
Soil pH: Acid, Alkaline, Neutral.
Flowering Time: Spring and summer.
Flower Colour: Lime green, yellow, light green.
Toxicity: Severe discomfort if eaten and the milky sap causes skin irritation.
Frequently asked questions about Euphorbias
Is euphorbia poisonous to cats, dogs or humans?
Yes. If ingested, all parts of euphorbia plants will cause severe discomfort to humans and their pets. Contact with the sap will irritate skin and eyes.
Do euphorbias need full sun?
Yes, most euphorbias like to grow in full sun but this species of euphorbia likes shade: E. amygdaloides var. robbiae.
How often should I water euphorbia?
Water newly planted euphorbias well in dry spells during their first two growing seasons. Keep the compost moist in container-grown euphorbias.
What should I plant with euphorbia?
Purples and mauves work well with the lime green of many euphorbias. Combine E. x martinii with Salvia nemorosa Caradonna or Allium Purple Sensation. The redder shades of E. griffithii Fireglow contrast in form and texture with the blue-grey leaves of Melianthus major.
Common pests and diseases with Euphorbias
Euphorbias are pretty resistant to pests and diseases, although sometimes powdery mildew can be a problem. Vigorous clump formers like E. amygdaloides and E. cyparissias ‘Fens Ruby’ can become invasive if not cut back when they become too vigorous.