<em>Armeria</em>, sea thrift: to plant, to grow, to care for

Description and botany

Armeria, commonly called “Sea thrift” or “sea pink”, belongs to family Plumbaginaceae. Genus includes more than 80 species of perennial plants growing naturally in mountains and coastal areas of northern hemisphere.

Armeria maritima is most common species in gardens. Also encountered species Armeria juniperifolia which offers a dwarf, compact habit not exceeding 8 cm in height and especially Armeria pseudarmeria which gave rise to a lovely selection, the ‘Ballerina’ series offering flowers larger than type and exceptional floribundity and vigour.

Relatively fast growing, this low plant grows in a compact, dense herbaceous tuft, forming rounded small cushions, which, planted en masse, strongly evoke grass and earned it the nickname “Sea thrift”. This groundcover, which tends to spread over time without ever becoming invasive, will not exceed 8 to 45 cm in height in flower, with a similar spread. Armerias have good longevity.

Armeria maritima – botanical illustration

From a cespitose, ramified stump emerge in spring rosettes of evergreen, linear or ribbon-like and long lanceolate leaves 1 to 20 cm long. They take on shades of medium green, dark green, blue‑green, green‑bronze and sometimes even purple and evoke, by their fineness and narrowness, grass-like foliage.

From this small cushion, luminous even in winter, rise stiff, smooth stems of varying length bearing at their tip the dense, spherical heads of the inflorescences. Perched on their stiff peduncles, usually well above the foliage, flattened or cup-shaped small flowers 1 to 4 cm in diameter appear in spring, tightly packed in compact, globose pompom-like clusters.

Flowers most often display all shades of pink, from very bright pink to pure mauve‑lilac and pink‑red but are sometimes white in some varieties. Flowering, remarkably long, begins in April–May and does not finish until August and can sometimes be perpetual in late summer.

Armeria is truly an easy little plant. From mountainous origins, it has retained its accommodating character and the robustness of plants that grow alone on dry slopes. Very hardy (-15°C sometimes well beyond), it can be cultivated in all our regions.

It is a full-sun plant that likes poor, very well‑drained soils, even sandy or slightly calcareous. Unpretentious, it even tolerates sea spray, and copes perfectly with wind and drought.

While fully playing its role as groundcover, in rockeries or as an edging, it can also be placed in an alpine garden or in pots, tubs and windowboxes.

Some flower colours : Armeria pseudarmeria ‘Ballerina Red’, Armeria maritima ‘Düsseldorfer Stolz’, Armeria pseudarmeria ‘Ballerina Lilac’, Armeria maritima ‘Alba’

Main species and varieties

Most popular

Our favourites

Armeria maritima Düsseldorfer Stolz - Sea Thrift

Forms a beautiful blue-green cushion topped with small, vivid reddish-pink flowers. This variety forms a compact, dense tuft suitable as groundcover, in a rockery or as an edging.

• Flowering time June to October
• Height at maturity 15 cm

See the product sheet

Armeria juniperifolia Bevans Variety - Sea Thrift

A dwarf variety forming dense, low cushions. Colours are more intense; foliage is darker green and pompom flowers are a brighter pink than the type. A miniature groundcover ideal for a trough, scree or a container.

• Flowering time May to July
• Height at maturity 10 cm

See the product sheet

Armeria maritima splendens - Sea Thrift

This variety forms a compact, dense tuft notable for its long-lasting red to bright pink flowering. Ideal as groundcover, in a rockery and in an alpine garden or in containers, tubs and planters.

• Flowering time June to August
• Height at maturity 10 cm

See the product sheet

Armeria pseudarmeria Ballerina Red - Sea Thrift

Forms an elegant cushion of evergreen leaves covered with fairly large pompom flowers of a somewhat muted dark red. Versatile, it grows as groundcover, in rockeries or in containers in full sun.

• Flowering time June to October
• Height at maturity 20 cm

See the product sheet

Armeria pseudarmeria Ballerina Lilac - Sea Thrift

We love its small mauve flowers tightly packed into pompom heads. Plants of the Ballerina series offer larger flowers than the type, sturdier flower stems and are more prolific and vigorous.

• Flowering time June to October
• Height at maturity 20 cm

See the product sheet

Armeria pseudarmeria Ballerina White - Sea Thrift

We like its large pure white flowers with a green centre. A very hardy and floriferous variety to plant anywhere in a container or in a dry garden.

• Flowering time June to October
• Height at maturity 20 cm

See the product sheet

Armeria maritima Vesuvius - Sea Thrift

An unusual variety with bronze foliage that is adorned from spring with small bright pink flowers. Very compact.

• Flowering time June to October
• Height at maturity 25 cm

See the product sheet

 

Planting

Where to plant Armeria or Sea thrift

Very easy to grow, resistant both to cold (sometimes down to -20°C) and to drought, to wind or sea spray, Sea thrift can be planted throughout France. From its montane origins, it has kept an undemanding character and is able to grow by itself on the seafront and in holiday gardens without watering. Its good resistance to drought makes it a plant well adapted to Mediterranean climate.

It prefers rather austere growing conditions. It only requires very well-drained, dry, even poor soil, including calcareous types. It will adapt very well to sandy soils of the coast.

Winter flooding is fatal to it, excess water is its only enemy: it absolutely needs a very free-draining soil, neither heavy nor waterlogged. If in doubt, plant on a mound or on a well-drained slope.

Give it a clear area without trees around that would shade it because it requires full sun to flower well.

This perfect groundcover will be an excellent alternative plant to grass on sandy ground and in sunny, hard-to-reach areas of the garden, thereby avoiding weeding.

It is rockery plant par excellence. It is also indispensable in front of perennial beds and in wild-looking mixed borders, to which it brings a lot of lightness. Miniature species (Armeria juniperifolia) will be perfect for a trough or a pot.

It will establish along a path, a border or a fence, to flower on low walls, in paving joints and on a rocky scree.

When to plant Armeria or Sea thrift

Plant Armeria or Sea thrift in garden in spring, from March to May in cold climate when risk of frosts has passed, or from September to November elsewhere.

How to plant Armeria or Sea thrift

In open ground

Armeria or Sea thrift benefits from being planted in drifts of 9 to 10 plants per m2, spaced 20 to 30 cm apart for a beautiful homogeneous tapetum.

In heavy soils, add coarse sand or gravel at planting to improve drainage.

• Dig a hole three times wider than rootball
• Plant without burying the collar
• Backfill with excavated soil
• Firm lightly
• Water generously at establishment; thereafter it will do without watering

In pots

The Sea thrift thrives in pots, window boxes or alpine troughs, alone or in combination. Substrate must be very free-draining to avoid stagnating moisture at roots. Place in full sun.

• In bottom of a large pot 30 cm in diameter, spread a good drainage layer (gravel or clay balls)
• Plant in a mixture of potting compost, garden soil and gravel
• Protect from winter rains by sheltering in a greenhouse during bad weather
• Mulch and water regularly

→ Learn more about planting Armeria maritima in a pot with Virginie

Care and maintenance

Sea thrift is a perennial really undemanding: it grows on its own without care and does not need watering once well established. Ideal for weekend gardens or gardens without gardeners!

It needs regular watering at the start of cultivation, afterwards it will manage on its own.

In a pot, give it a little more regular watering to keep the potting mix slightly moist, especially if drought sets in. Once a month, feed the plant with a fertiliser for flowering plants to encourage flowering and keep it vigorous; do the same when repotting. In bad weather, even though it is not afraid of cold or frost, you can protect it from freezing rain by sheltering it in a greenhouse.

Remove dead flowers as they fade to encourage flowering and keep small cushions looking tidy.

Withered clump of Armeria maritima (photo Gertjan van Noord – Flickr)

In autumn after flowering, clean and cut back clumps to ground level to keep a vigorous, compact tuft.

Every two or three years, divide clumps to restore vigour.

Potential diseases and pests

In open ground, Armeria or sea thrift is not very prone to disease. Rust is its main enemy, especially in spring when it forms reddish pustules on leaves. Cut and destroy affected leaves. Then treat this fungus by spraying with nettle manure or horsetail manure.

Infestations of red spider mites and aphids can occur in greenhouses.

Propagation

Dividing clumps in spring, on well-established 2–3-year-old plants, remains the simplest and quickest method of propagating Sea thrift. Sowing Sea thrift seeds is possible in a cold frame in spring or autumn but will yield unpredictable results.

• Use a spade to lift the clump
• Separate a few divisions from the clump
• Replant these divisions immediately in the garden in well-draining soil
• Water thoroughly

Associate

With excellent drought and sea-spray tolerance, ornamental all year round, Sea thrift is indispensable in dry gardens, in a mineral garden and in maintenance-free gardens, seaside, alpine or Mediterranean holiday gardens where it forms superb flowering tapeta all year round.

Planted in numbers, it provides contrast with its vibrant hues, either in pastel versions within mixes of cool colours — mauve, purplish or white — or in more complementary pink/green-yellow combinations with allium moly and achilleas.

Flowers of this mat-forming perennial will open abundantly in spring and summer, surrounded by other sun-loving perennial groundcovers such as Caucasian rockcress, aubrieta, crucianella, moss phlox, hardy geraniums, snow-in-summer (Cerastium tomentosum), Mexican fleabane (Erigeron karvinskianus) and heart-leaved globularia.

In a border, it will sit alongside campanulas, the everlasting Helichrysum angustifolium and coreopsis.

On edge of a mineral bed, it will pair with sedums, achilleas and add a pastel note, scattered among grasses.

An example of a pairing in dry soil: Armeria maritima, Festuca glauca, Sedum spectabile ‘Herbstfreude’, Achillea millefolium ‘Red Velvet’

It will find its place edging a summer bed alongside miniature carnations, perennial flax, phacelia, love-in-a-mist (Nigella damascena), Penstemon, Cosmos, gaura, Eryngium, Nepeta and ornamental alliums.

It adds structure to pink/mauve-inspired themes, surrounded by lavenders, asters and miniature carnations, creeping gypsophila, roses of low habit, artemisias and small blue thistles.

In a stone trough or pot, pair it with alyssum.

→ Discover other ideas for pairing with Armeria in Virginie’s advice sheet