Silene uniflora
sea campion
Western and northern Europe (coastal)
Overview
Silene uniflora is a low, cushion- to mat-forming perennial 10-25 cm (4-10 in) tall, with sprawling, branching stems rising from a woody base and a deep taproot. The paired leaves are grey-green, fleshy, oval, and waxy, an adaptation to wind and salt. From late spring it bears white flowers 2-2.5 cm (0.8-1 in) across, each with five notched petals held above a markedly inflated, balloon-like calyx netted with pink or purple veins. The flowers are usually solitary or in small groups at the stem tips. It forms loose grey hummocks on cliffs, shingle, and walls, anchored by the taproot against wind and spray. Plants are deep-rooted and somewhat short-lived, and are intolerant of rich, wet, or shaded conditions, becoming leggy and flopping in fertile borders. Top growth is semi-evergreen, persisting in mild winters and dying back in hard cold. It grows in poor, sharply drained, sunny sites and tolerates salt, drought, and exposure, but declines where drainage is poor or competition is strong.
Native Range
Silene uniflora is native to the coasts of western and northern Europe, from Iberia to Scandinavia and Iceland, with scattered inland sites on mountains and gravel. It grows on sea cliffs, shingle beaches, dunes, and rocky ground, and occasionally on mountain ledges and riverbanks. It is not native to North America.Suggested Uses
Planted in rock gardens, gravel gardens, dry stone walls, raised beds, and coastal and seaside plantings. Used as a drought- and salt-tolerant filler on poor, sunny, sharply drained ground. Its dislike of rich, wet soil makes it ill-suited to conventional moist borders.How to Identify
Appearance
Size & Dimensions
Height4" - 10"
Width/Spread8" - 1'4"
Reaches mature size in approximately 2 years
Bloom Information
Flowering runs from May to August, peaking in early summer. The white flowers open above their inflated calyces over many weeks, opening more fully towards evening and releasing a faint scent. Papery seed capsules follow within the persistent calyces through late summer.
Detailed Descriptions
Foliage Description
Grey-greenGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grow Silene uniflora in poor, gritty, sharply drained soil in full sun, such as rock gardens, gravel, raised beds, and dry walls. It tolerates salt, wind, and drought and suits coastal and seaside gardens, but rots in wet or heavy soils. The plant is hardy and needs no winter protection across temperate zones. Sow seed in spring or autumn, or take basal cuttings in early summer. Trim the cushions back after flowering to keep them compact, as plants grow leggy in rich or shaded sites. It needs no feeding and little water once established.Pruning
Shear the cushions back lightly after flowering to keep a tight habit and prompt fresh growth. Remove dead or straggly stems in spring. Cut back hard only if plants become woody and open at the centre.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons