Euphorbia lathyrus (Spurge) — Clump-forming, upright or spreading sub-shrub

Overview

Euphorbia lathyrus 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 lathyrus 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.

About

Euphorbia lathyrus is a clump-forming perennial sub-shrub in the spurge family with an upright to spreading habit and narrow, often glaucous leaves. Foliage is frequently blue‑grey and can develop a red tint in autumn. Plants produce their flowers from May to September. Most forms prefer well-drained light soils and do not tolerate winter wet.

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 lathyrus is a perennial member of the Euphorbiaceae that forms upright or spreading clumps of narrow, often glaucous leaves; some plants show a red tinge to foliage in autumn. As a clump-forming sub-shrub it keeps a clear outline through the year where leaves persist or semi-persist. Flowering runs from May to September, providing a long season of interest from the plant's inflorescences. Place it in full sun to partial shade; woodland forms will tolerate dry shade where light levels are reduced. It prefers light to moderately fertile loam, sand or chalk and will grow on acid, neutral or alkaline soils provided they are well drained — most plants dislike winter wet. Aspect can be any and it succeeds in either exposed or sheltered positions. The UK hardiness range H4–H7 indicates plants will survive from average to fully hardy UK conditions, so selection of a free‑draining site is more important than winter protection in many gardens. Use Euphorbia lathyrus at the front or middle of a sunny border on light soils, in gravel or rock gardens, or on drier shaded edges of woodland where soil is not waterlogged. Expect flowering from May to September.

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 lathyrus 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

Care notes

Pruning and caring for Euphorbia lathyrus

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 lathyrus?

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 lathyrus?

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

What soil does Euphorbia lathyrus need?

Euphorbia lathyrus 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 lathyrus?

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 lathyrus hardy in the UK?

Euphorbia lathyrus 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 lathyrus?

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.

More in the Euphorbia genus

Browse all Euphorbia →