Eryngium planum

RHS Plant Profile
blue eryngo

Other common names

flat-leaved eryngo

Plants for pollinators
Herbaceous Perennial

A robust perennial forming a clump of rounded dark green basal leaves and upright, branched stems bear deeply-lobed, blue-tinged, spiny leaves and small, blue terminal flowerheads with narrow, spiny bracts 2.5cm long, in summer and early autumn

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.1-0.5 metres

Size

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

Growing Conditions

Chalk Loam Sand
Moisture
Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
West–facing or South–facing
Exposure
Sheltered
Hardiness
H5
Drought Resistance
Yes

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Apiaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming
Genus
Eryngium can be annuals, biennials or perennials with simple or divided leaves, often spiny edged, and cone-like flower-heads often surrounded by an involucre of conspicuous spiny bracts
Name Status
Correct
Plant Range
Central Europe to W Himalaya

How to Grow

Cultivation

Grow in dry, well-drained poor to moderately fertile soil in full sun, with protection from winter wet

Propagation

Propagate by seed in containers in a cold frame as soon as ripe; insert root cuttings in late winter; propagate by division during spring, although they may be slow to re-establish

Suggested planting locations and garden types

  • City and courtyard gardens
  • Coastal
  • Cottage and informal garden
  • Gravel garden
  • Wildlife gardens
  • Flower borders and beds

Pruning

Tidy plants after flowering; ideal for flower arranging - cut the stems before the flowers are fully open

Pests

May be susceptible to leaf and bud eelworms, and slugs and snails

Diseases

May be susceptible to root rot and powdery mildews