Globe thistle

Sun

Full sun; light shade is tolerated, but stems may lean and flowering may be reduced.

Water

Water regularly during establishment, then mainly during prolonged dry spells. Avoid persistently wet soil, especially in winter.

Soil

Well-drained sandy, chalky or loamy soil; tolerates poor soil and a broad pH range. Heavy clay needs improved drainage.

Height

2-4 ft (0.6-1.2 m)

Spread

1.5-2.5 ft (0.45-0.75 m)

Flowers

Mid- to late summer; spherical steel-blue to violet-blue flower heads.

Foliage

Deeply lobed, spiny-edged, grey-green leaves with pale, felted undersides; lower leaves can become untidy after flowering.

Growth

Moderate

Care needed

Low

• Water new plants deeply when the root zone dries; reduce watering once established.
• Avoid rich feeding and heavy manure, which encourage soft, floppy growth.
• Keep mulch clear of the crown; gravel mulch suits dry sites.
• Support stems early if the site is windy or the soil is unusually fertile.
• Leave established clumps undisturbed unless they become crowded or flower poorly.

Pruning. Cut faded flower stems back to a healthy leaf to limit self-seeding and sometimes encourage a smaller second flush. Alternatively, leave the seed heads for winter structure, then cut dead stems to ground level in late winter or early spring.

Early spring

Cut down remaining dead stems before new shoots lengthen.

Spring

Plant in a sunny, freely draining position and water through establishment.

Late spring

Add discreet supports where needed before flowering stems become tall.

Summer

Water during prolonged drought and check young growth for aphids.

Late summer

Remove fading heads before seeds ripen if you do not want seedlings.

Autumn

Leave selected seed heads standing for structure and check that the crown is not buried under wet debris.

Winter

Take root cuttings from dormant plants if you want more plants of the same form.

• Repeat small groups through a sunny perennial border to create a rhythm of blue spheres.
• Pair with fine-textured ornamental grasses for contrast between rounded heads and airy foliage.
• Use in gravel gardens with yarrow, lavender and other plants that need good drainage.
• Place behind lower-growing plants that hide the declining basal leaves after flowering.

Garden styles it suits: Cottage garden, New perennial (prairie), Dry gravel garden, Pollinator garden, Low-maintenance and Blues and silvers.

Plant it with: Yarrow, Russian sage, Catmint, Lavender, Purple coneflower and Feather reed grass.

Wildlife: The flowers provide nectar and pollen for bees and other pollinating insects, including butterflies. Retained seed heads may provide food for seed-eating birds.

• Crown or root rot in wet soil: improve drainage or move the plant to a raised, drier position; avoid winter waterlogging.
• Flopping stems in shade or rich soil: provide more sun, stop high-nitrogen feeding and support stems early.
• Aphids on young shoots: wash off small colonies with water and allow ladybirds and other predators to help.
• Powdery mildew: improve air circulation, avoid drought stress and remove badly affected foliage.

Not known to be toxic to people, cats, dogs or horses; no particular part is recognized as poisonous, though species-specific information is limited. The prickly leaves and flower heads can scratch skin and irritate the mouth if chewed.

• Great globe thistle (Echinops sphaerocephalus)

  Usually taller and coarser, with pale grey-white rather than strongly blue flower heads and conspicuously hairy, often glandular stems.

• Blue sea holly (Eryngium planum)

  Has smaller, oval to egg-shaped flower heads surrounded by a visible collar of pointed bracts, rather than the nearly spherical, bract-free-looking heads of globe thistle.

Echinops comes from Greek words meaning hedgehog and appearance, referring to the spiny flower heads, while ritro derives from an old Greek name for a thistle.

Propagation. Sow seed in spring; seedlings may differ from named cultivars. Take root cuttings in winter to preserve a cultivar, or divide clumps carefully in early spring, keeping substantial roots with each piece.

Accepted botanical name

Echinops ritro

In the US and Canada

Introduced in the lower 48 states.

Native range

Albania, Altay, Austria, Baltic States, Bulgaria, Central European Rus, Czechoslovakia, East Aegean Is., East European Russia, France, Germany and Greece.

Measured

Average height 53 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.