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

Description and botany

Helichrysum, helichrysum or immortelle belongs to vast family Asteraceae, like daisies and asters.

Genus comprises 500 species of herbaceous perennials, annuals or sub-shrubs with often woody, aromatic stems, native to dry, sunny hills around Mediterranean basin, notably Italy but also Asia, South Africa and Australia.

Among most common are:

• perennial immortelles such as Helichrysum italicum, Corse immortelle, Italian immortelle, curry plant whose very aromatic foliage gives off a powerful curry scent; common immortelle or “dune immortelle” (Helichrysum stoechas) with downy leaves and erect, tuft-like flowers; and woolly immortelle (Helichrysum petiolare) recognisable by its grey, woolly leaves and available in many cultivars.
• less hardy cousin, Helichrysum bracteatum (also found as Bracteantha bracteata or bracted everlasting) which is perennial in native range but grown as annual in our climates. It is prized for its multicoloured heads essential for dried bouquets.

Plant quickly forms a dense, rounded, upright tuft (Helichrysum italicum, Helichrysum stoechas) or a spreading, trailing habit (Helichrysum petiolare), depending on Helichrysum species. It consists of woody stems reaching 0.25 to 0.80 m, even 1.20 m in height depending on species. Bracted everlasting shows faster growth and flowers just two to three months after sowing.

Perennial immortelles are notable for winter-persistent, very aromatic foliage evoking curry scent. Stems, more or less ramified, bear leaves whose shape and colour vary with Helichrysum species.

Leaves are alternate, similar to lavender, usually with a narrow lamina, 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 foliage is remarkable for grey, grey-green or grey-white tones, some cultivars of woolly immortelle such as ‘Variegata’ stand out with variegated green-and-yellow leaves.

This silver-hued shrub is covered in flowers from June to September, sometimes until first frosts. This summer and autumn flowering is another attraction. However, perennial and annual immortelles also differ by distinctly different flowers.

From woody crown emerge fine leafy stems each bearing small globular inflorescences at tip.

Helichrysum italicum and its perennial companions display small yellow heads 3 to 8 cm across gathered in corymbs at stem tips. Plant then becomes covered with numerous flowers opening as spherical pom-poms. Devoid of ligules and surrounded by long, paler bracts—fewer than those of bracted everlasting—they consist of tightly packed florets resembling small golden-yellow buttons; Helichrysum in Greek means “golden sun”.

Some species, such as oriental immortelle, show flowers that change colour as they open, from pale yellow to rich sun yellow.

Bracted immortelles have such a distinctive character they stand out at once, much like their cousin chrysanthemum. They open as solitary heads 2 to 8 cm across at stem tips. Flowers of Xerochrysum bracteatum feature a corolla lacking ray florets, replaced by dried, translucent bracts that imitate petals. These thin, rigid bracts, papyraceous like paper, resemble mother-of-pearl and have the peculiarity of not wilting, giving this flower its name “immortelle”. They open around a centre of tiny tubular florets marked by a ring of darker colour. They produce, when dried, small seeds with egret that sometimes self-sow, dispersed by wind.

Flowering of Helichrysum italicum and Helichrysum bracteatum

Originally golden-yellow and pearly, flowers now come in very varied colours thanks to many selections, from gaudy to soft shades. They are most often sold in mixed colours. These bright, scaly corollas occur in many hues from white to purple via lilac, salmon, Tyrian pink, red, bronze and dark yellow and orange. Some are bicolour. Heads are often double, many hybridizations having produced, for example, Helichrysum monstruosum or double bracted monstrous immortelle, another immortelle with giant flowers!

This melliferous flowering, remarkably generous in all immortelles, renews throughout summer, attracting many pollinating insects especially bees.

These lovely luminous heads make magnificent long-lasting dried bouquets, much appreciated in floristry, particularly bracted immortelles. Immortelles are also superb in fresh bouquets.

While bracted immortelles tolerate only light frosts around -1 to -2°C and are grown as annuals, perennial immortelles are mostly fairly hardy (usually down to -10 to -15°C). All appreciate warm, sunny exposures or light 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 damp. Bracted immortelles will perform better in cool, enriched soil where they are more floriferous.

Immortelles easily find place in a natural garden and especially in a dry garden to flower . They fit perfectly into annual and perennial borders, mixed borders, but also in pots and containers on balconies and terraces.

All immortelles have long been known for medicinal properties. From Italian immortelle is extracted an essential oil used for anti-inflammatory and analgesic virtues and reputed for anti-ageing action.

Fresh leaves of perennial immortelles can be used in cooking to flavour salads, fish, grills, rice or marinades; however, as they are not very digestible, it is preferable to use sparingly. In some countries, dried flowers of dune immortelle are consumed as an infusion.

Main species and varieties

Most popular

Our favourites

Helichrysum italicum

Its beautiful grey evergreen foliage gives off a very intense curry scent, noticeable metres away. Grows equally well in pots or 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

Flowers that do not fade and warm colours perfect for creating the most beautiful dried bouquets. Sow anywhere in sun: beds, borders, containers or banks.

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

See the product sheet

Helichrysum petiolare Silver

A creeping perennial species forming magnificent silver tapeta. 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 lovely pearly shell-pink salmon hue. Will flower enthusiastically throughout summer in rockeries or wilder parts of garden.

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

See the product sheet

Planting

Where to plant Helichrysum?

Helichrysum or everlasting is a Mediterranean plant whose hardiness varies according to species. Perennial everlastings such as Helichrysum italicum tolerate cold down to about -15°C, and grow throughout France; they are very common in Mediterranean gardens. In very cold, wet regions, perennial everlasting may however begin to suffer from around -10°C, as this plant dislikes moisture, especially in winter. Bracted everlastings are tender perennials that are grown as annuals, to be reseeded each year in garden beds.

By origin, all everlastings have retained a taste for heat and arid soils. Helichrysum are sun-loving plants for dry gardens par excellence!

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

Perennial everlastings are essential in all natural gardens, especially in dry gardens or in seaside gardens as they tolerate sea spray. They are also useful for filling gaps in a perennial border. Perennial species are a boon for dry ground where they form pretty silver tufts all season in rockeries and dry banks, in borders or as groundcover in the most inhospitable parts of garden. Curry plant naturally also finds a place in a vegetable garden, in an herb bed or border.

Annual everlastings are sown widely in ornamental gardens as well as in cutting gardens and will flower all summer until October in pots, flowering hanging baskets and window boxes on balcony or terrace.

When to plant perennial everlasting?

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 everlasting?

In ground

Everlasting absolutely needs perfect drainage. In heavy, compact or clay soil, 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 all round (allow 4 to 6 plants per m2).

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

• Dig hole 2 to 3 times wider than rootball
• Work soil well to loosen
• Lighten with coarse sand
• Spread a bed of gravel at bottom of hole
• Place plug plant in centre of hole without burying collar too deep
• Backfill, firm gently
• Water well at planting then moderately, without drowning roots

Helichrysum bracteatum (syn. monstrosum)

In pot

Potting mix must be well draining to avoid stagnant moisture that would rot roots. Woolly everlasting (Helichrysum petiolare), less hardy than other perennial companions, is generally regarded as an annual and, with its trailing habit, is better suited to pot or hanging-basket culture than other perennial everlastings.

• In a large container of at least 50 cm diameter, spread a good layer of gravel or clay balls
• Plant in a mix of compost, garden soil and river sand or pumice
• Water at planting then sparingly, only in dry periods and never let water stand in saucers
• Place in full sun

Follow our advice to plant our plug plants in window boxes

When and how to sow annual strawflower?

Bract everlasting seeds are sown in spring, under cover February–March–April or directly in situ after frosts from April for flowering that will begin in July.

Under cover

• Sow seeds as thinly as possible in a seed tray filled with good seed compost
• Cover seeds lightly with compost
• Firm down and water copiously with a fine spray
• Keep seedlings in light, under cover heated to 20°C and keep moist until emergence, which takes 2 to 3 weeks
• Pot on seedlings when about 5 cm tall into individual buckets
• Plant out in garden in late May when temperature is warm enough, spacing 30–40 cm in all directions
• Pinch stems so they ramify a little more; they will produce more flowers!

Direct sowing in open ground or in pot

In open ground

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

• Sow seeds broadcast, as thinly as possible, in well-prepared, airy soil enriched with compost
• Cover them lightly with compost
• Firm down and water with a fine spray until emergence
• After emergence, thin seedlings leaving only the most robust young plants every 30–40 cm
• Pinch tips of young stems to encourage them to ramify

In pot

You can also choose to sow directly in a 30 cm diameter pot or in a 30 cm long planter, in a mix of potting compost, sand and garden soil. After emergence, thin so that only three seedlings remain per container.

Helichrysum italicum

How to care for everlasting flowers?

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

Care of perennial Immortelles

In first summer, water once a week then only during prolonged drought, and always without 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 while always allowing substrate to dry out well between waterings.

The 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 sparingly during winter and put back out in May.

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

Pruning of perennial Immortelles

Pruning is not essential; it simply helps preserve a neat habit. They tolerate regular but not drastic pruning in late winter, which would prevent formation of old wood, because parts that lignify into hard wood gradually become bare and will no longer produce new shoots.

1. At end of season, simply cut flower stems with a pruning shear to prevent flowers setting seed and needlessly exhausting the plant: hang heads upside down to dry for making dried bouquets!
2. Pruning should be done only on shoots of the year that are still green and tender: avoid touching old wood, as it will not regrow. In early spring (March–April): prune most of the young shoots to 2 or 3 cm from the old wood, no more.

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

Harvesting leaves

The harvest of very aromatic fresh leaves of Helichrysum, or Curry Plant, can be done year-round as required to flavour dishes and salads.

Care of bract-bearing Immortelles

The bract-bearing Immortelle grows very quickly, so it will appreciate slightly richer soil enriched with a liquid feed for flowering plants once during the season for in-ground plants and once a month from June to September for specimens in pots.

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

Deadhead regularly to encourage new blooms and extend flowering. However, allow some flowers to set seed: you can sow them the following year. Plants are discarded at end of season.

Harvesting dried immortelle flowers

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

Pick flowers in dry weather, slightly before they are fully open. Hang these flowering stems upside down in a dry, dark and well-ventilated place. When leaves are dry, remove them from the stems as they bleach while drying and will be unattractive in your bouquets. And discover our collection of flower seeds for dried bouquets.

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

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

Potential diseases and pests

Not very susceptible to disease, Immortelles have few enemies.

In warm, humid weather, especially at the end of summer, they can be prone to powdery mildew, which leaves a white coating on the foliage. As a preventive measure: water at the base without wetting leaves and spray nettle manure, a horsetail decoction or Bordeaux mixture. If affected: remove and burn diseased parts and follow our advice to fight powdery mildew.

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

Propagation of perennial everlastings

Perennial immortelles 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 10–12 cm lengths of non-flowering stems
• 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 following spring when temperatures have warmed
• Pinch stems to encourage bushier growth
• Water in at planting then sparingly

→ Learn more about Helichrysum propagation in our advice sheet

Associate

Like their southern cousins lavender or santolina, the Perennial immortelles always bring a Mediterranean touch to a garden that is both exotic and elegant. They are essential in dry, sun‑baked gardens, where they form pretty silvery clumps all year round.

In a rockery, Helichrysum italicum or H. petiolare will keep company with other Mediterranean perennials equally undemanding and used to drought, such as creeping rosemary, a small potentilla, Tanacetum haradjanii, artemisias or yellow sedums. You can also pair them with other perennials that require the same growing conditions, such as Gazania, woolly artemisia 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 lavenders, they will create an aromatic border of glaucous or grey foliage redolent of garrigue. With their bright foliage that persists through winter, when paired with delosperma and dianthus they also make good groundcover for Mediterranean shrubs such as oleanders, cistus or olive trees.

Their vivid yellow flowering also echoes blues or purples offered by ceanothus or buddleias. For a cacophony of yellow blooms, plant them near Achilleas, helianthemums, coreopsis and Helenium, while they will provide a lovely contrast with the complementary blue of Perovskia, Caryopteris, Nepeta and salvias. On a dry bank, combine them with small shrubs for dry soil such as Hertia cheirifolia, Hypericum olympicum, creeping broom and dry‑site euphorbias.

A hanging‑basket idea: Helichrysum petiolare ‘Silver’, Pelargonium ‘Amelit’ and dusty miller (‘Silver Dust’, for example)

In a sun‑loving naturalistic meadow, perennial immortelles will take part in abundant, colourful summer scenes with highly 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 immortelles will sit alongside a few airy grasses such as Stipa pennata or Stipa tenuifolia, or next to Agaves or opuntias for more contemporary combinations.

In the vegetable garden, you can pair the curry plant with other easy‑going aromatic perennials such as thyme and salvias.

Meanwhile, the bracted immortelles or annual immortelles, with their slightly old‑fashioned look and endlessly variable bright hues, are indispensable in cottage gardens, where they add an exotic note to colourful mixed borders or beds. Flowering from mid‑summer to early autumn, mixed with Helenium, Gaillardia, autumn sedums, late‑flowering perennials or African daisies and other saturated‑colour annuals, they bring vivid colour to a season that can be a little lean on blooms.

An example combination: Helichrysum bracteatum (the colour you want or a mix), Alchemilla (such as A. epipsila) and Bacopa ‘Snowtopia White’

They also go well with the bold blooms of dahlias. Their shiny flower heads sit within a massing of light grasses such as Pennisetum (fountain grass), Miscanthus, Stipa pennata and foxtail barley, which lighten their strongly‑formed flowers. Asters and chrysanthemums are also good companions to extend their flowering into autumn.

In a cutting garden, pair them with statices and amaranths — they are among the easiest flowers to dry! In a trough or window box, mix them with zinnias, small dahlias blended with the feathery spikelets of small grasses.

→ More ideas to pair Helichrysum in our care sheet!