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Key characteristics

Family: Apiaceae
Height: 2 to 3 feet
Width: 1 to 2 feet
Flower color: Steel-blue, spiky, thistle-like blooms
Foliage color: Dark green, spiny leaves with a silvery-blue tint
Bloom time: Summer
Light: Full sun
Water: Low; drought-tolerant
Maintenance: Low; requires minimal care
Growing zone: USDA zones 4 to 9
Wildlife: Attracts bees, butterflies, and other pollinators

Perennials

Eryngium x zabelii ‘Big Blue’

Big Blue Sea Holly

Eryngium x zabelii 'Big Blue' is an eye-catching perennial known for its vivid metallic blue color and dramatic, spiky appearance. From mid-summer to early fall it produces long-lasting, globe-shaped flower heads composed of tiny florets, surrounded by spiny, deeply serrated bracts. As the flowers mature, the intense blue color deepens, making them even more remarkable. The sturdy stems and leaves also take on a bluish hue, further enhancing its striking ornamental appeal.

Light

Full sun

Water

Low; drought-tolerant

Bloom time

Summer

Find this plant

Works well in

Borders
Sun Gardens
Pollinator Gardens
Waterwise Gardens
Cut Flower Gardens

Companion plants

Coreopsis · Bearded irises · Bee balm · Yarrow · Ornamental grasses · Garden phlox

Design tip

Summer flowers carry the middle of the season, so place it where the bed needs color once spring bulbs fade. Give it open sun and room to fill out, and repeat it in threes or fives so the planting reads as one sweep instead of scattered dots.