Eryngium × olivierianum 'Neptune's Gold'PBR

RHS Plant Profile
eryngo 'Neptune's Gold'

Other common names

sea holly 'Neptune's Gold'

Synonyms

Eryngium × zabelii 'Neptune's Gold'

Herbaceous Perennial

An upright, herbaceous perennial to about 50cm. The foliage and flower bracts are spiny and yellow green, while the flowers are electric blue. Rounded heads of tiny flowers appear in mid- to late summer, and the seedheads often remain decorative into winter

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

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

Growing Conditions

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

Position

Full sun
Aspect
South–facing or West–facing or East–facing
Exposure
Exposed or 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
Accepted

How to Grow

Cultivation

Grow in dry, well-drained soil that is poor to moderately fertile. Full sun is essential as is protection from winter wet

Propagation

Propagate by root cuttings in late winter

Suggested planting locations and garden types

  • City and courtyard gardens
  • Gravel garden
  • Patio and container plants
  • Architectural
  • Coastal
  • Cottage and informal garden
  • Prairie planting
  • Banks and slopes
  • Cut flowers
  • Flower borders and beds

Pruning

Although you can cut back flower stems after flowering the seedheads are a very attractive feature so are usually left over winter

Pests

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

Diseases

May be susceptible to root rot and powdery mildews