<em>Echinops</em>: planting, growing and care

botany

The echinops are spiny plants, mostly perennials (annuals and biennials also occur), and very hardy. They bear spherical inflorescences at tops of erect stems. Native to Europe, central and eastern Asia, and tropical Africa. Nearly 190 species are known. Most commonly cultivated are Echinops ritro, sphaerocephalus and bannaticus. In wild, echinops occur mainly in relatively arid media, notably on dry short grass meadows, rocky slopes, fallow land and uncultivated ground. This explains why echinops are undemanding as to soil type, grow well in poor soils and tolerate drought rather well. In France, three species are found in wild: Echinops ritro, Echinops sphaerocephalus and Echinops exaltatus.

Echinops belong to family Asteraceae (plants formerly called “Compositae”, comprising nearly 33,000 species). This is family of daisies, dandelions and oxeye daisies… but also of thistles and knapweeds, to which echinops are fairly close. Echinops are sometimes called “Globe thistle”. All these plants have inflorescences in heads, gathering a large number of tiny flowers. Unlike dandelions and oxeye daisies, which have flat heads (all flowers on same horizontal plane), echinops bear spherical heads.

Echinops recall sea hollies, Eryngium, by their blue–grey colours, silvery stems, graphic inflorescences and spiny aspect.

Echinops sphaerocephalus: botanical illustration

Etymologically, name Echinops means in Greek “resembling a hedgehog” (Echinos: hedgehog, and opsis: resembling), and refers to spherical inflorescences. Echinops is also name of a small mammal, a genus of hedgehog. Plant echinops bears various common names: azurite, blue thistle, globe thistle, blue urchin, blue globe…

Echinops grow quickly, forming clumps of erect, ramified stems topped by spherical inflorescences. They can measure between 60 cm and 1.50 m in height, but are often around one metre. Echinops giganteus is an exception: it can reach up to five metres! Among species commonly grown, Echinops sphaerocephalus are somewhat taller than others.

Echinops have a very open, airy habit, allowing sight through them. They can create beautiful scenes with light, when spherical inflorescences catch sun rays, or by playing with frost in winter. Stems are sturdy and long-lasting; if not cut back, they remain in place over winter.

Echinops flower in mid-summer, from July until August or September. Flowering can sometimes be extended by pruning, removing faded flowers… which encourages plant to bloom again.

They then bear, at stem tips, blue balls (spheres), which give echinops its nickname “Blue globe”. These distinctive inflorescences resemble small sea urchins and also recall flowering of Alliums. Flowers are all attached at centre, on a receptacle, and radiate outwards. As they are thin and elongated, they give impression of a sphere bristling with little points. These inflorescences are very graphic, forming perfect, well-rounded spheres. They usually measure between 3 and 5 cm in diameter… but those of Echinops giganteus are much larger, measuring between 10 and 20 cm in diameter! A true giant echinops.

These inflorescences are therefore spherical heads, gathering many flowers attached to same axis. Flowers are actually tiny, but each inflorescence groups a very large number! Flowers are tubular. Each is composed of five fused petals (five lobes), and five sepals. Inside tube formed by petals are five stamens (male sexual organs bearing pollen), bluish-grey in colour, and a style. Flowers are hermaphrodite. They are also surrounded by spiny bracts.

Inflorescences are generally blue–grey in colour; a somewhat mysterious shade, both deep and at the same time light, silvery, metallic. Unlike many other flowers, it is not a bright, clear colour. Variety Echinops ‘Arctic Glow’ is distinguished by white flowers. Space between flowers is always a little darker, in shadow, adding contrast to flowering and making each little “point” stand out.

Flowering stems of echinops are ideal for bouquets. They are very decorative in a vase, both during flowering and afterwards. You can cut flowers and dry them, hanging heads upside down.

Echinops is melliferous: flowers are much appreciated by insects. They attract bees and butterflies. These pollinate flowers in exchange for nectar offered by flowers.

Flowering of Echinops sphaerocephalus (photo Drew Avery) and detail of an inflorescence of Echinops ritro (photo Patrick Ch. Apfeld)

Leaves of Echinops are spiny, elongated and nicely cut. They are dentate, irregular, thick and coriaceous. Echinops graecus stands out by extremely fine foliage. Leaves bear small spines along edge of lamina, allowing plant to protect itself from herbivores tempted to eat it. Most prickly seems to be – by far – Echinops spinosissimus; its lamina is very reduced but extremely spiny! Leaves of echinops measure between 10 and 30 cm long. They are alternate, placed one after the other along stems. Those at base of stems are larger than those near top. Lamina is attached directly to stem, without petiole. It is even embracing, more or less surrounding stem.

Foliage is deciduous, it disappears in winter with cold.

Generally, leaves are dark green (sometimes more or less grey) on upper surface, and silvery beneath. Most often, upper surface is glabrous (without hair), and underside tomentose.

A leaf of Echinops bannaticus, foliage of Echinops sphaerocephalus (photo Lucy Downey) and underside of a leaf of Echinops exaltatus (photo Rolf Engstrand)

Stems bearing leaves and flowers have a beautiful silvery colour. In Echinops ‘Star Frost’, inflorescences have same shade, making plant relatively uniform.

Echinops tends to self-sow… It can become somewhat invasive. But it is fairly simple to avoid volunteer seedlings by cutting stems after flowering.

Seeds are small elongated achenes, topped by a bristle egret, which allows them to fly away. As in many Asteraceae, fruits of echinops are wind-dispersed. This is what allows plant to reach new territories. Infructescences (seedheads) recall those of dandelions. They have a very decorative aspect, making Echinops interesting in garden even in winter. They are also appreciated by birds.

Main varieties of Echinops

Most popular varieties

Echinops ritro

One of the most widely grown Echinops! Its inflorescences have a metallic blue tint before the small flowers open, then become a truer blue. Leaves are green on upper surface but white and downy beneath. Found in the wild in southern France.

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

See the product sheet

Echinops bannaticus Blue Globe

This Echinops produces spherical inflorescences in summer, of a fairly intense blue, darker than other varieties. It can rebloom (in early autumn) if you prune it after flowering.

• Flowering time August, September
• Height at maturity 1,50 m

See the product sheet

Echinops ritro Veitch’s Blue

This variety bears grey-green foliage and flowers in spherical heads, of a rather dark metallic blue. It can also rebloom in autumn after being pruned.

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

See the product sheet

Our favourite varieties

Echinops bannaticus Star Frost

This Echinops is distinguished by its silvery-white inflorescences, which harmonise with the stems that bear them. The plant then appears entirely silver.

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

See the product sheet

Echinops sphaerocephalum Arctic Glow

A fairly tall Echinops producing silvery-white spheres in summer, slightly tinged with green. Stems tend to take on a rather dark reddish hue, creating a striking contrast with the paler flowering.

• Flowering time August, September
• Height at maturity 1,20 m

See the product sheet

Planting Echinops

Where to plant?

Echinops are plants that like heat and need good light: plant them preferably in full sun, possibly in part shade.

Echinops are easy to grow and not demanding about soil type. They tolerate calcareous ground well. What matters most is that substrate is well draining, as they dislike stagnant water. If ground tends to retain water, improve drainage (add gravel, coarse sand, etc.).

Echinops do very well in poor, low-fertility and relatively dry soils. No need to give them compost or fertiliser. On the contrary, avoid planting them in too-rich soil, as they would then produce tall, weak stems that would need staking. Plant will look better in poor soil. Echinops also appreciate deep, loose substrate, allowing their roots to penetrate well.

As echinops like stony, free-draining soil, you can quite happily plant them in a rockery, with plants that tolerate drought and enjoy full sun. They are also perfect for edging, alongside other perennials… or at back of border, for the larger varieties!

If location suits them, echinops will tend to self-seed generously! They can even naturalise.

When to plant?

You can plant them in spring (April–May) or in autumn (September–October). Avoid frosts or periods of intense heat.

How to plant?

We recommend planting echinops in groups rather than singly; or scatter several plants within the same border, alongside perennials flowering in summer. Allow about 50 cm spacing, although this also depends on variety chosen.

1. Dig a planting hole. No need to add compost, but you can improve drainage by adding gravel or coarse sand, or by planting on a mound.
2. Remove your echinops from its pot and plant it.
3. Replace soil around it, and firm gently.
4. Water generously.

Continue watering until plant is well established.

Echinops ritro (photo Acabashi)

Care

Echinops do not need much maintenance. Except in dry spells, they do not really need watering. In any case, avoid excess moisture.

Feel free to cut flower stems to make bouquets! They last a long time in a vase. You can dry them by hanging them upside down, flowers pointing down. Ideally place them in a dark, warm, dry and well-ventilated room.

You can either leave the stems in place for winter, as they remain decorative even after flowering, or cut plant back in autumn. This will prevent self-seeding, because when it settles in a spot it can become somewhat invasive.

Cutting flowers when faded can allow plant to flower again! Some varieties of Echinops are perpetual, able to produce a new flowering in autumn.

If exposed to wind, Echinops may require staking to help keep stems upright, especially with taller varieties.

As Echinops appreciates poor soils, there is no need to give it fertiliser or compost. You can optionally lay a layer of mulch around it, as this will limit weed growth and prevent soil drying out too quickly.

We suggest renewing your plants every three to four years, as over time they become less vigorous.

Echinops is rarely affected by diseases or pests. It can occasionally be attacked by aphids. It also dislikes excess moisture, which can cause it to rot.

Propagation: sowing, division, propagation by cuttings

Echinops can be propagated by sowing, division of clumps or propagation by cuttings. You can also lift volunteer sowings and transplant them. Propagating Echinops will allow you to renew your young plants, which may become exhausted over the years.

Sowing

You can sow Echinops in spring, around April, from seeds you have harvested or bought. Sowing can be done in open ground (after last frosts), or in pots.

If you wish to sow directly in situ :

1. Choose a sunny position on well-draining soil. If necessary, add some coarse sand to improve water infiltration.
2. Prepare seedbed by breaking up clods of earth, remove large stones and weed roots. Level ground to obtain a flat, even surface.
3. Scatter seeds on surface and cover them very lightly.
4. Water with a fine spray.

Continue watering in the weeks that follow.

You can also start them in pots. In that case, prepare pots with good seed compost, place seeds and cover them with a very thin layer of growing medium: they need a little light to germinate. Water with a fine spray. You can plant out as soon as there is no longer any risk of frost.

Dividing clumps

Dividing clumps is a good technique to regenerate young plants. It is done in early spring or in autumn. We recommend doing this every three to four years.

1. Choose a clump large enough, several years old
2. Lift it gently, digging wide enough not to damage the roots
3. Separate it into several fragments
4. Replant each fragment in a new position, after preparing the ground.
5. Water.

Propagation by root cuttings

You can also propagate Echinops by root cuttings, in winter or spring.

1. Prepare a pot with potting compost mixed with sand.
2. Choose a well-developed clump and lift it carefully, without damaging the roots.
3. If necessary, remove excess soil so roots are clearly visible.
4. Choose a lateral root, fairly thick, healthy and well formed
5. Cut it close to base of plant to obtain a fragment 5 to 10 cm long. Use a sharp, disinfected knife and make a clean cut.
6. Replant original clump in ground and water it.
7. Then place root cutting in pot, under a few centimetres of medium, laying it horizontally.
8. Cover with compost
9. Water.
10. Place pot in frost-free shelter, in a bright position.

Water regularly so medium remains moist (without excess moisture) until establishment. It should take two to three months to develop.

→ Find out more about Echinops propagation by cuttings in our tutorial.

Companion planting in the garden

To accompany echinops, prefer choosing other plants that also thrive in sun and well-drained soil.

You can place echinops in a rock garden, with rock-garden geraniums, sedums, lavender, achilleas, Eryngium, santolina… For example, create a raised bed with a few large stones and plant drought-tolerant plants between them. You can also add a mineral mulch around plants (gravel, pumice…). The result will be a garden that needs very little maintenance.

Also don’t hesitate to combine echinops with plants in grey or silvery tones. Benefit from the wooly, very soft leaf of Stachys byzantina… but also the silvery leaves of santolinas, Helychrisum italicum, Senecio cineraria, Cerastium tomentosum, Convolvulus cneorum, wormwoods (Artemisia schmidtiana or ‘Powis Castle’), or the knapweed Centaurea pulcherrima… Also enjoy the impressive foliage of Cynara cardunculus (cardoon, ornamental artichoke)! For small touches of colour, rely on rose campion, Lychnis coronaria.

Conversely, you can contrast echinops’ cool tone with warm colours. Daylilies, rudbeckias and echinaceas, achilleas with yellow or red flowers (‘Terracotta’ or ‘Paprika’), etc. will warm the bed, creating a superb contrast. Echinops are perfect with larger, brightly coloured flowers. You can thus compose a superb summer border or a very colourful mixed border! Echinops add a contrast of form and a lightness that showcases brighter flowers and broader foliage.

Because they have a light, airy, wild aspect, echinops can easily fit into naturalistic gardens. Plant them alongside superb verbena hastata (Verbena hastata), burnets, agastaches, knautias… Especially since echinops are good melliferous plants. Use them to create a garden favourable to biodiversity. You can also include Nigella damascena with its superb, very delicate blue flowers.

You can place echinops in a very natural, wild-style garden. Echinops ‘Arctic Glow’ with Anemone ‘September Charm’ and Pennisetum villosum / Nigella damascena (photo H. Zell) / Verbena hastata (photo Cody Hough) / Knautia macedonica ‘Melton Pastels’

With their very structured look and their original, metallic colour, echinops make it possible to create a modern, graphic garden! Dare contrasts, unusual hues, black, purple, white, silver… Choose other highly graphic plants, such as Eryngiums, ferns, bamboos, horsetails, Japanese maples, ophiopogon and grasses.

Echinops can also fit into a romantic garden, with roses, astrantias, thalictrums, clematis, agastaches, perovskias… Not forgetting delicate flowering of Japanese anemones.

You can also choose other very light-looking plants to accompany them: gaura, perovskia, knautia, nigella… Echinops are perfect in combination with grasses: pennisetum, miscanthus, calamagrostis, and above all, Stipa pennata! Also discover the small ovoid spikes of Lagurus ovatus! You will obtain a very light bed, both natural and modern in style.

→ Discover other great ideas for pairing with Echinops in our advice sheet!

An idea of pairing Echinops sphaerocephalus, Astrantia major, Aconitum ‘Stainless Steel’ and Lavender (photo Nicole et Patrick Mioulane – MAP)