Sea campion – info, planting, care and tips

Sea campion (Silene uniflora)
Sea campion (Silene uniflora)

With its radiant white calyxes, the multi-flowered sea campion beautifies wall crowns, joints and rock gardens in summer.

Profile of sea campion:

Scientific name: Silene uniflora

Plant family: pink or carnation family (Caryophyllaceae)

Other names: –

Sowing time: spring

Planting time: spring to autumn

Flowering period: June to August

Location: sunny

Soil quality: stony to sandy, calcipholous, low in nutrients, low in humus

These information are for temperate climate!

Use as spice herb: salad, wild herb

Use in: groundcover, roof greening, borders, group planting, dry stone walls, roof garden, natural garden, rock garden

Winter hardiness: hardy, USDA Plant Hardiness Zones: 3 (-37 °C / -35 °F)

Bee and insect friendly: Yes

Plant characteristics and classification of sea campion

Plant order, origin and occurrence of sea campion

The sea campion (Silene uniflora, formerly Silene maritima) is one of the 600 to 700 species of the genus of campion (Silene), which has undergone different divisions in the botanical nomenclature over the centuries. Silene uniflora belongs to the botanical family of carnations (Caryophyllaceae). As its name describes, the sea campion grows mainly on beach and coastal cliffs along the western European coast and the northern Baltic Sea coast. In Iceland, the plant is native to the whole island. Because of its similar appearance, it is sometimes confused with the bladder campion (Silene vulgaris).

Characteristics of sea campion


The sea campion, which grows at a low height of about 25 centimeters (10 in), is a perennial and herbaceous plant that forms dense clusters at the appropriate location. In summer the plant shows a dense carpet of flowers. The bare stems of Silene uniflora lignify in the lower part. The plant is very frost hardy.


The fleshy leaves of the sea campion are gray-green in color and broadly lanceolate in shape. Like the stems they are also hairless. The leaves sit alternately on the shoot and are covered with a thin layer of wax. In mild areas the leaves of Silene uniflora remain green throughout the winter.


The highly expanded, purple patterned calyx of sea campion has five white petals at the crown. These reach a diameter of about 2.5 centimeters (1 in). The blossoms is between June and August. Its flowers are very popular with butterflies.


The flowers develop into attractive brown seed capsules up to 10 millimeters (0.4 in) long, which open from the top in five parts to release the tiny warty and kidney-shaped seeds.

Sea campion – cultivation and care


Naturally, the sea campion loves the proximity to waters and a full sunny location. It grows on shores and beaches, but also in crevices and on slopes.


The typical soil is permeable, stony, sandy or gravelly, which should be calcareous and strongly alkaline. As a halophyte (salt plant) it also appears again and again at road sides overloaded by road salt.


Always plant sea campion in groups, for example on the edge of the bed as a border plant or in small groups. You will need about 10 to 15 plants per square meter (10 sq ft.) for a comprehensive planting. Compact garden soil must be loosened and provided with a drainage of gravel or sand before planting.

Care / Watering / Fertilization

Sea campion is extremely easy to care for and is completely undemanding in the right location. In very dry summers, occasional watering is recommended. You can completely do without fertilizers.


If the clusters become too large, the plant can be divided in autumn or spring. However, this is not necessary for the vitality of the plant.


It is best to propagate the sea campion by division, because the clusters grow by themselves over the years. It is also possible to sow the light-germinating seeds all year round. Plant the seeds in the desired location and keep them moist during the four-week germination period.

Diseases and pests

For the robust sea campion, neither diseases nor pests are of concern in garden cultivation.


The sdea campion is very hardy down to -37 °C / -35 °F. There are no special meaures for overwintering necessary.

Use in the garden

As a magnet for butterflies, the sea campion should not be missing in any natural garden. For the decoration of wall crowns, dry walls, roof gardens, stairs or steppe and rock gardens it serves likewise outstanding and comes in combination with lilacbush, moss phlox and stonecrop into one’s own. As a bordering plant, Silene uniflora decorates bed borders and paths. And also as decoration in tubs and underplanting of high stems, the slightly overhanging flower is particularly beautiful.

The leaves are edible raw as an ingredient in salads or as wild herb.


A popular garden variety of the sea campion is Silene uniflora ‘Robin Whitebreast’. Its calyxes are not purple, but have a greenish pattern. Its cup-shaped white petals are slightly curled at the edges. The variety ‘Druett’s Variegated’ has leaves with white edges. ‘Rosea’ is a rare, pale pink selection.

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