Euphorbia dulcis (sweet spurge) — Clump-forming, upright or spreading sub-shrub

Overview

Euphorbia dulcis is a clump-forming, upright or spreading sub-shrub perennial in the genus Euphorbia, part of the Euphorbiaceae family, with evergreen, semi-evergreen or deciduous; narrow, often blue-grey or glaucous, sometimes red-tinted in autumn foliage. Euphorbia dulcis grows best in full sun to partial shade; the woodland species tolerate dry shade, and tolerates light to moderately fertile loam and sand or chalk soils and acid and neutral or alkaline pH. Its UK hardiness is rated H4-H7. It is native to Belgium, Flemish Region, Walloon Region and Portugal Continental.

About

Euphorbia dulcis is a clump-forming perennial spurge with narrow, often blue-grey leaves that may become red-tinted in autumn. It grows as an upright or spreading sub-shrub and flowers from May to September. Plants suit full sun to partial shade on light to moderately fertile, well-drained soils. Take care when pruning because the milky sap can irritate skin and eyes.

Wikipedia contributors, CC BY-SA 4.0 — Euphorbia dulcis

About the genus

Euphorbia is a large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae.

Wikipedia contributors, "Euphorbia", CC BY-SA 4.0 — Euphorbia

In the garden

Euphorbia dulcis belongs to the Euphorbiaceae and establishes as a clump-forming, upright or spreading sub-shrub with narrow, often blue-grey foliage. It is native to parts of western Europe, specifically the Flemish and Walloon regions of Belgium and continental Portugal, where it occupies well-drained, often calcareous soils. Give plants full sun to partial shade; woodland forms will tolerate dry shade. Soils can be light loam, sand or chalk and the species accepts acid, neutral or alkaline pH provided drainage is good — most plants dislike winter wet. Positions can be exposed or sheltered and it suits any aspect. With a UK hardiness range H4–H7 (average to fully hardy) Euphorbia dulcis will survive most garden locations, though heavy winter waterlogging reduces vigour. Use it where narrow, glaucous leaves are wanted: gravel borders and sunny mixed borders on chalky or sandy soils, or drier understorey spots beneath light-canopied trees. It flowers between May and September, adding a season-long presence rather than a single flush. When cutting back or handling flowerheads, wear gloves and eye protection because the milky sap is a genuine irritant.

Growing conditions

Best soil and position for Euphorbia

Sunlight: Full sun to partial shade; the woodland species tolerate dry shade
Soil type: Light to moderately fertile loam, sand or chalk
Soil pH: Acid, neutral or alkaline
Soil moisture: Well drained; most dislike winter wet
Aspect: Any
Exposure: Exposed or sheltered
UK hardiness: H4-H7

Plant details

Euphorbia dulcis size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright or spreading sub-shrub
Foliage: Evergreen, semi-evergreen or deciduous; narrow, often blue-grey or glaucous, sometimes red-tinted in autumn
Native to: Belgium, Flemish Region, Walloon Region, Portugal Continental
Toxicity: The milky sap is a genuine irritant to skin and eyes

Care notes

Pruning and caring for Euphorbia dulcis

Cultivation: Easy and largely self-sufficient given drainage. The milky sap is a genuine irritant to skin and eyes, so wear gloves and eye protection when cutting back and never handle the plant in strong sun. Most flower on stems produced the previous year, which makes correct timing of the cut essential. The spreading species can be invasive in loose soil, so site them accordingly.
Pruning: On the shrubby evergreen kinds, cut flowered stems right to the base once the bracts fade in summer, leaving this season's new shoots to flower next year. Cut herbaceous species down in late autumn.
Propagation: Divide herbaceous kinds in spring. Take basal cuttings of shrubby species in spring and rinse the cut end to stop the latex sealing it. Many self-seed freely.
Pest resistance: Rarely troubled by pests; aphids occasionally gather on soft new growth.
Disease resistance: Generally healthy. Euphorbia rust causes orange spotting and distorted shoots on some species and affected growth should be removed.

Frequently asked questions

How do I grow Euphorbia dulcis?

Easy and largely self-sufficient given drainage. The milky sap is a genuine irritant to skin and eyes, so wear gloves and eye protection when cutting back and never handle the plant in strong sun. Most flower on stems produced the previous year, which makes correct timing of the cut essential. The spreading species can be invasive in loose soil, so site them accordingly.

Where is the best place to plant Euphorbia dulcis?

Euphorbia dulcis prefers full sun to partial shade; the woodland species tolerate dry shade. It suits exposed or sheltered positions.

What soil does Euphorbia dulcis need?

Euphorbia dulcis grows best in light to moderately fertile loam and sand or chalk soil. It prefers acid and neutral or alkaline soil. Aim for soil that stays well drained; most dislike winter wet.

How do I prune Euphorbia dulcis?

On the shrubby evergreen kinds, cut flowered stems right to the base once the bracts fade in summer, leaving this season's new shoots to flower next year. Cut herbaceous species down in late autumn.

Is Euphorbia dulcis hardy in the UK?

Euphorbia dulcis has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.

How do I propagate Euphorbia dulcis?

Divide herbaceous kinds in spring. Take basal cuttings of shrubby species in spring and rinse the cut end to stop the latex sealing it. Many self-seed freely.

Is Euphorbia dulcis toxic?

The milky sap is a genuine irritant to skin and eyes.

More in the Euphorbia genus

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