Echinops ritro subsp. ruthenicus 'Platinum Blue'

RHS Plant Profile

globe thistle 'Platinum Blue'

Synonyms

Echinops ritro 'Platinum Blue'
Echinops ruthenicus 'Platinum Blue'

Herbaceous Perennial

Buy this from Plant Nurseries
10 Suppliers

A compact, clump-forming herbaceous perennial 80-90cm tall, with silvery-green, thistle-like leaves. Bright, metallic-blue, spherical flower heads are borne on tall, branched, silvery stems in late summer; comes true from seed

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 2–5 years
Max Spread: 0.1-0.5 metres
Max Height: 0.5-1 metres

Growing Conditions

Chalk Loam Sand

Moisture: Well–drained
pH: Neutral or Alkaline or Acid

Position

Full sun Partial shade

Aspect: South–facing or East–facing or West–facing
Exposure: Exposed
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

H1A: under glass all year (>15C)
H1B: can be grown outside in the summer (10 - 15)
H1C: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20): H7
Drought Resistance: Yes

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Asteraceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Clump forming, Columnar upright
Genus: Echinops can be annuals, biennials or perennials with simple or pinnately lobed, spiny leaves and spherical blue or whitish flower-heads
Name Status: Accepted

How to Grow

Cultivation

Best in poor, well-drained soil in full sun but will tolerate most soils in full sun and can tolerate partial shade

Propagation

Propagate by division in spring or autumn or by root cuttings in winter. Propagate by seed in mid-spring - comes true from seed

Suggested planting locations and garden types

Coastal
Cottage and informal garden
Gravel garden
Wildlife gardens
Flower borders and beds
Cut flowers

Pruning

Can cut back after flowering. Alternatively leave flower heads over winter for architectural interest and for wildlife habitats.

Pests

May be susceptible to aphids

Diseases

Generally disease-free