<em>Helichrysum</em>, curry plant, everlastings: sow, plant, care for

Description and botany

Helichrysum, helichrysum or Immortelle belongs to the large family Asteraceae, like daisies and asters.

The genus includes some 500 species of herbaceous perennials, annuals or sub-shrubs with often woody, aromatic stems, native to the arid hills of sunny Mediterranean regions, notably Italy, but also Asia, South Africa and Australia.

Among the most common are:

• the perennial Immortelles such as ‘Helichrysum italicum, Corsican Immortelle, Italian Immortelle, Curry Plant‘ whose very aromatic foliage gives off a powerful curry scent, the common Immortelle or “dune Immortelle” (Helichrysum stoechas) with downy leaves and erect, tuft-like flowers, and the woolly Immortelle (Helichrysum petiolare) recognisable by its grey, woolly leaves and available in many cultivars.
• their less hardy cousin, Helichrysum bracteatum (also known as Bracteantha bracteata or bracted everlasting) which is a perennial in its native country but grown as an annual in our climates. It is prized for its multicoloured heads that are essential in dried bouquets.

The plant quickly forms a dense, rounded, erect tuft (Helichrysum italicum, Helichrysum stoechas) or a mat-forming, trailing habit (Helichrysum petiolare), depending on Helichrysum species. It consists of woody stems reaching 0.25 to 0.80 m, sometimes up to 1.20 m in height depending on species. Bracted everlasting shows faster growth and can flower just two to three months after sowing.

The perennial Immortelles are notable for very aromatic winter-persistent foliage reminiscent of curry. Stems, more or less ramified, bear leaves whose shape and colour vary according to Helichrysum.

Leaves are alternate, similar to those of lavender, most often with a narrow lamina that is linear, lanceolate to elliptical, acuminate, sometimes heart-shaped in Helichrysum petiolare. They measure 2 to 15 cm long and are downy, even particularly woolly in perennial species, smooth and green in annuals.

Some perennial Immortelles have attractive silvery foliage: Helichrysum italicum and Helichrysum petiolare ‘Silver’

If this foliage is remarkable for its grey, grey-green or grey-white tones, some cultivars of the woolly Immortelle such as ‘Variegata’ stand out with green foliage variegated with yellow.

This silvery shrub is covered with flowers from June to September, sometimes until first frosts. This summer and autumn flowering is another attraction of the plant. However, perennial and annual Immortelles also differ in the appearance of their flowers.

From the woody crown emerge fine leafy stems, each bearing small globular inflorescences at their tips.

Helichrysum italicum and its perennial companions display small yellow heads 3 to 8 cm in diameter gathered in corymbs at the end of each stem. The plant is then covered with numerous flowers that open in spherical pompons. Devoid of ligules and surrounded by long, paler bracts — fewer than those of bracted everlasting — they are formed of closely packed florets evoking small golden-yellow buttons; Helichrysum in Greek means “golden sun”.

Some species, such as the oriental Immortelle, offer flowers whose colours change from pale yellow to golden yellow as they open.

The bracted Immortelles have such a distinctive character that they stand out at a glance, much like their cousin the chrysanthemum! They open as solitary heads 2 to 8 cm in diameter at the end of each stem. Flowers of Xerochrysum bracteatum are characterised by a corolla lacking ray florets, which are replaced by dried bracts that mimic petals. These thin, rigid bracts, papyraceous like a sheet of paper, resemble nacre and have the particularity of not withering, which earned this flower its name “everlasting”. They open around a centre of tiny tubular florets marked by a ring of darker colour. They produce, on drying, small seeds with egrets that sometimes self-seed, dispersed by the wind.

Flowering of Helichrysum italicum and Helichrysum bracteatum

Originally pearly golden yellow, they now come in a very wide range of flower colours thanks to many selections, from the most vivid to the softest shades. They are most often offered as colour mixes. These bright, scaly corollas are available in many shades from white to purple via lilac, salmon, magenta-pink, red, bronze and dark yellow and orange. Some are bicoloured. Heads are most often double, the many hybridisations having produced, for example, Helichrysum monstruosum or monstrous double-bracted Immortelle, another Immortelle with giant flowers!

This melliferous flowering, remarkably generous in all Immortelles, renews uninterruptedly throughout summer, attracting many pollinating insects, particularly bees.

The attractive bright heads make it possible to create magnificent long-lasting dried bouquets, much prized by florists, especially the bracted Immortelles. Immortelles are also superb in fresh bouquets.

While bracted Immortelles tolerate only light frost of around -1 to -2 °C and are grown as annuals, perennial Immortelles are for the most part fairly hardy (at least down to -10 to -15 °C). All appreciate warm, sunny exposures or partial shade, tolerating drought and poor or calcareous soils. They grow in well-drained or shallow soil and do not tolerate acidic or heavy soils as they fear winter wetness. Bracted Immortelles perform better in fresh, enriched soil where they prove more floriferous.

Immortelles easily find their place in a natural garden and especially in a dry garden to flower rockeries or wilder areas. They fit wonderfully into annual and perennial flower beds, borders, mixed borders, but also in pots and planters on balconies and terraces.

All Immortelles have long been known for their medicinal properties. In particular, Helichrysum italicum yields an essential oil used for its anti-inflammatory and analgesic virtues and reputed for its anti-ageing action.

Fresh leaves of perennial Immortelles can be used in cooking to flavour salads, fish, grills, rice or marinades; they are not very digestible, so consumption should be limited. In some countries, dried flowers of the dune Immortelle are consumed as an infusion.

Main species and varieties

Most popular

Our favourites

Helichrysum italicum

Its beautiful grey evergreen foliage and very intense curry scent are noticeable several metres away. It grows equally well in a pot or in garden in well-draining soil!

• Flowering time August to October
• Height at maturity 50 cm

See the product sheet

Helichrysum italicum Plug

Its very aromatic leaves give off a powerful curry scent and can be used in cooking. Plant in vegetable patch or rockery in garden!

• Flowering time July to October
• Height at maturity 35 cm

See the product sheet

Strawflower Double Flowered Mixed Seeds - Helychrysum monstruosum

Non-fading flowers and warm colours perfect for creating the most beautiful dried bouquets. Sow anywhere in sun: flowerbeds, borders, containers or slopes.

• Flowering time August to October
• Height at maturity 1 m

See the product sheet

Helichrysum petiolare Silver

A creeping perennial immortelle species forming magnificent silver tapetum. More tender than its perennial cousins, it will bring an elegant touch to pots and hanging baskets.

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Strawflower Double Salmon Seeds - Helychrysum monstruosum

This selection offers very large scaly flowers in a pretty shell-pink shade with a pearly sheen. It will flower enthusiastically throughout summer in rockeries or slightly wild areas of garden.

• Flowering time August to October
• Height at maturity 80 cm

See the product sheet

Planting

Where to plant Immortelle?

Helichrysum or Immortelle is a Mediterranean plant whose hardiness varies by species. Perennial immortelles such as Helichrysum italicum tolerate cold reasonably well, down to around -15°C, and grow throughout France; they are very common in Mediterranean gardens. In very cold, damp regions, perennial Immortelle may however begin to suffer from around -10°C, as this plant dislikes moisture, especially in winter. Immortelles with bracts are frost-tender perennials that are usually grown as annuals, sown again each year in our gardens.

All immortelles have retained a taste for heat and arid soils from their origins. Helichrysum are sun and dry-garden plants par excellence!

They are undemanding plants that grow very easily in full sun, in any shallow, poor, rather calcareous soil, even stony and gravelly, but in all cases very well drained, They adapt to ordinary soil as long as it does not retain water. To flower well, however, bract Immortelles will need a slightly fresher, enriched soil throughout the season.

Perennial Immortelles are essential in all natural gardens, particularly in dry gardens or in coastal gardens as they are not harmed by sea spray. They are also useful for filling gaps in a perennial border. Perennial species are a boon for dry ground, where they form attractive silvery clumps all season in rockeries and dry banks, in borders or used as groundcover in the most inhospitable areas of the garden. Curry plant naturally finds a place as well in a vegetable garden, in a bed or an herb border.

Annual immortelles will also be sown widely in the ornamental garden and in a cut-flower garden and will flower all summer until October in pots, flowering hanging baskets and window boxes on balcony or terrace.

When to plant perennial Immortelle?

Our plug plants of Helichrysum are planted in spring from March to May depending on region when temperatures rise, or in autumn in September–October in warm climate.

How to plant perennial Immortelle?

In ground

Immortelle absolutely needs perfect drainage. In soil that is too heavy, compact or clayey, incorporate gravel or coarse sand into bottom of planting hole. If ground is too wet, plant on a slope or in a raised rockery. Space plants about 30 to 40 cm apart in all directions (allow 4 to 6 plants per m2).

Before final planting, we recommend potting on our young plug plants into buckets filled with potting compost to harden them off. Put them outside as soon as risk of frost is definitely over.

• Dig a hole 2 to 3 times diameter of the rootball
• Work soil well to break it up
• Lighten with coarse sand
• Spread a layer of gravel on bottom of hole
• Place plug plant in centre of hole without burying the collar too deeply
• Backfill, firm gently
• Water well at planting then moderately without drowning roots

Helichrysum bracteatum (syn. monstrosum)

In pots

Potting medium must be well draining to avoid stagnant moisture that would rot roots. Woolly Immortelle (Helichrysum petiolare), less hardy than other perennials, is generally treated as an annual and, with its trailing habit, is better suited to growing in pots or hanging baskets than other perennial immortelles.

• In a large container of at least 50 cm diameter, lay a good layer of grit or clay balls
• Plant in a mix of potting compost, garden soil and river sand or pumice
• Water at planting then sparingly, only in drought and never allow water to stand in saucers
• Position in full sun

Follow our advice to plant our plug plants in window boxes correctly

When and how to sow annual immortelle?

Bract-bearing strawflower seeds are sown in spring, under cover February–March–April or directly in place after frosts from April for flowering starting in July.

Under cover

• Sow seeds as sparsely as possible in a seed tray filled with good seed compost
• Cover seeds lightly with compost
• Firm surface and water well with a fine spray
• Keep sowings in light, under heated cover at 20°C and keep moist until germination, which takes 2–3 weeks
• Prick out seedlings when about 5 cm tall into individual buckets
• Plant out in garden late May when temperature is warm enough, spacing 30–40 cm all round
• Pinch stems to encourage more ramification; they will produce more flowers!

Direct sowing in open ground or pot

In open ground

Flowering will start later, from August with this method because bract strawflower seeds can only be sown once all risk of frost has passed and on well-warmed soil, consequently not before April or May.

• Sow seeds thinly by broadcast on well-cleared, friable soil enriched with compost
• Cover seeds lightly with compost
• Firm surface and water with a fine spray until germination
• After germination, thin out keeping only the sturdiest young plants every 30–40 cm
• Pinch tip of young stems to encourage ramification

In pots

You can also opt for direct sowing in a pot 30 cm in diameter or in a 30 cm-long trough, in a mix of potting compost, sand and garden soil. After germination, thin out so only three seedlings remain per container.

Helichrysum italicum

How to care for everlastings?

Once well established, Immortelles, whether perennial or annual, require very little maintenance. They are rarely diseased provided soil remains well drained.

Care of perennial Immortelles

First summer, water once a week then only during prolonged drought and always avoid excess. They are accustomed to long arid summers typical of Mediterranean climate and require no watering once well rooted.

In a pot, water a little more often, always allowing substrate to dry out between waterings.

Perennial Immortelles are undemanding plants for which no fertiliser is necessary.

In regions with harsh winters, bring in the most tender Helichrysum such as Helichrysum petiolare to protect from frost and rain, water them sparingly during winter and put back outside in May.

And follow our advice to care for perennials and protect plants from cold.

Pruning perennial Immortelles

Pruning is not essential; it simply helps keep a neat shape. They tolerate regular but not drastic pruning in late winter; drastic cuts prevent formation of old wood because parts that become lignified into hard wood gradually become bare and will not produce new shoots.

1. At season’s end, simply cut flower stems with pruning shear to prevent flowers setting seed, which would unnecessarily exhaust plant: hang stems upside down to dry to make dried bouquets!
2. Pruning should be done only on shoots of the year that are still green and tender: avoid cutting old wood, which will not re-sprout. In early spring (March–April): cut back most young shoots to 2 or 3 cm from old wood, no further.

For more information, see our advice sheet: How to prune Helichrysum?

Harvesting leaves

Harvest fresh, very aromatic leaves of Helichrysum or Curry Plant year-round, as needed to flavour dishes and salads.

Care of bract-bearing Immortelles

The bract-bearing Immortelle grows very quickly and therefore prefers slightly richer soil enriched with a liquid fertiliser for flowering plants once during season for plants in open ground and once a month from June to September for container plants.

It will also need more regular watering than its perennial relatives, which will make it even more floriferous.

Remove faded flowers regularly to encourage new ones and extend flowering period. However, allow a few flowers to set seed: you can sow them the following year. Plants are discarded at season’s end.

Harvest of dried immortelle flowers

Everlastings, whether perennial or not, owe their name to the fact that they do not wither, even after flowering, making them one of the best flowers for dried bouquets.

Pick the flowers in dry weather, just before they are fully open. Hang these flowering stems upside down in a dry, dark and airy place. When leaves are dry, remove them from the stems because they turn white as they dry and will be unattractive in your bouquets. And discover our collection of flower seeds for dried bouquets.

→ Find out more about drying and storing Helichrysum, or curry plant, in our tutorial!

Helichrysum italicum is among effective moth-repellent plants: find out how to use it for this purpose.

Diseases and potential pests

Not very susceptible to disease, Immortelles have few enemies.

In hot, humid weather, especially late summer, they can be susceptible to powdery mildew, which leaves a white, felt-like coating on the foliage. As a preventive measure: water at soil level without wetting leaves and spray with nettle manure, a horsetail decoction or Bordeaux mixture. If infected: remove and burn affected parts and follow our advice on combating powdery mildew.

They can also be targeted by aphids and caterpillars: spray with water mixed with black soap to dislodge them.

Propagation of Perennial Immortelles

Perennial everlastings such as Helichrysum italicum or Italian everlasting are easily propagated in June by herbaceous cuttings or by semi-ripe cuttings in July-August.

How to take cuttings of Helichrysum or everlasting

• Take 10 to 12 cm long stem sections without flowers
• Remove lower leaves from stem
• Insert cuttings into buckets filled with potting compost and river sand
• Keep substrate moist until rooting
• Protect young seedlings from frost throughout winter
• Plant out next spring when temperatures have warmed
• Pinch stems to encourage bushier growth
• Water at planting then sparingly

→ Find out more about Helichrysum propagation in our advice sheet

Associate

Just like their southern cousins, lavender or santolina, perennial everlastings always add a Mediterranean touch to a garden that is both evocative and elegant. They are indispensable in dry gardens and wild, sun‑baked places, where they form pretty silvery clumps throughout the year.

In a rockery, Helichrysum italicum or H. petiolare will keep company with other Mediterranean perennials that are equally undemanding and drought‑tolerant: creeping rosemary, a small potentilla, Tanacetum haradjanii, Artemisia or yellow sedums. You can associate them with other perennials that require identical growing conditions such as Spanish rock‑plants, woolly armoise, and Cerastium tomentosum.

An example of a Mediterranean‑inspired combination: Perovskia atriplicifolia ‘Blue Spire’, Helichrysum italicum, Lavender, Rosemary and Santolina

Beside an Artemisia, santolinas and a few clumps of lavender, they will form an aromatic border of glaucous or grey foliage redolent of garrigue. With their bright foliage that persists through winter, teamed with delosperma and dianthus, they are also excellent plants to cover the base of Mediterranean shrubs such as oleanders, cistus or olive trees.

Their bright yellow flowering will also echo the blues or purples offered by ceanothus or buddleias. For a riot of yellow flowers, place them near Achillea, helianthemum, coreopsis and helenium, while they will provide a lovely contrast with the complementary blues of Perovskia, Caryopteris, Nepeta and salvias. On a dry bank, pair them with small dry‑soil shrubs such as Hertia cheirifolia, Hypericum olympicum, creeping broom and dry‑site euphorbias.

An idea for a hanging basket: Helichrysum petiolare ‘Silver’, Pelargonium ‘Amelit’ and cineraria (‘Silver Dust’ for example)

In a sunlit naturalistic meadow, perennial everlastings will contribute to abundant, colourful summer displays with very floriferous dry‑soil perennials such as Echinops, Erigeron karvinskianus, Echinacea, hollyhocks, Centaurea moschata, Leucanthemum, Agastache and astragalus. In a scree garden, the silvery clumps of perennial everlastings will sit alongside feathery little grasses such as Stipa pennata or Stipa tenuifolia, or with Agaves or opuntias for more contemporary combinations.

In the vegetable patch, pair the curry plant with other easy‑going aromatic perennials such as thymes and salvias.

Meanwhile, bracteate everlastings or annual everlastings, with their slightly old‑fashioned charm and endlessly variable bright colours, are perfect for country gardens, adding an exotic note to colourful mixed‑borders or bed edges. Flowering through midsummer into early autumn, mixed with heleniums, gaillardias, autumn sedums, late‑flowering perennials or with vividly coloured annuals such as African daisies, they bring saturated colour at a time of year when many beds begin to fade.

An example combination: Helichrysum bracteatum (in desired colour or mixed), Alchemilla (such as A. epipsila) and Bacopa ‘Snowtopia White’

They also work well with the bold flowers of dahlias. Their shiny flower heads sit comfortably within a massing of lightweight grasses such as Pennisetum or bottlebrush grass, Miscanthus, Stipa pennata and foxtail barley, which will lighten their strongly defined blooms. Asters and chrysanthemums are also good companions to carry their flowering through to autumn.

In a cut‑flower garden, pair them with statice and amaranths — they are among the easiest flowers to dry! In a planter, mix them with zinnias, small dahlias and the plumy spikelets of small grasses.

→ More ideas to pair Helichrysum in our advice page!