Eryngium – Blue Sea Holly – Water Wise Pollinator

Grows 24-36″ tall

Eryngium planum

Sea holly is a perennial plant in the Apiaceae (carrot) family. It grows in stiff erect clumps 1 to 3 feet tall and 1 to 2 feet wide and provides interest in the landscape with its unusual spiky flower heads that resemble a thistle. The name Eryngium is a Greek reference to the spiny nature of this genus of plants. The species name planum means flat.

Plant in the full sun in well drained sandy or loamy soil. In fact, the more sun this plant recieves the more intensely colored the blue flowers will be. It is tolerant of a wide range of soil pH.

This plant blooms from June through September and often profusely during the summer. It has ornamental interest in the colorful, spiny, thick, and white-veined leaves. Steel blue flowers with a ring of spiky ornamental bracts are useful for cutting or drying. Dead head flowers to maintain a tidy appearance cut the plant back after flowering at the end of the summer. The plant sometimes self seeds, slowly moving around the garen but rarely becomes a problem. Propagation is most easily accomplished by separating plantlets from the base of the parent plant. Choose a location wisely as sea holly does not transplant well.

Sea holly is tolerant of poor or dry soils, and its spiny leaves are resistant to browsing by rabbits and deer. It withstands salty, coastal winds and also does well in inland gardens. Use in small groupings in a cottage garden, rock garden or as a specimen in a perennial border planting. Plant in a container or along a patio to enjoy the unusual blooms that are frequented by butterflies.

Insects, Diseases, and Other Plant Problems: Aphids, slugs, and snails may appear. Susceptible to root rot (needs dry soils and leaf spot diseases. In rich soils plants may grow leggy and topple over.

• ‘Blue Cap’
  Clump forming, blue tinged leaves
• ‘Blue Glitter’
  Intense blue flower color, quick maturity
• ‘Blue Hobbit’
  Dwarf reaching only 1 ft. tall and wide, purple blue flower heads
• ‘White Glitter’
  Silver ivory flowers, silver green stems

• ‘Blue Cap’
  Clump forming, blue tinged leaves
• ‘Blue Glitter’
  Intense blue flower color, quick maturity
• ‘Blue Hobbit’
  Dwarf reaching only 1 ft. tall and wide, purple blue flower heads
• ‘White Glitter’
  Silver ivory flowers, silver green stems

• Attributes: Genus: Eryngium Species: planum Family: Apiaceae Life Cycle: Perennial Recommended Propagation Strategy: Division Seed Country Or Region Of Origin: E. Central Europe to Mongolia and W. Himalaya Wildlife Value: The flowers attract butterflies and bees. Dimensions: Height: 2 ft. 0 in. – 3 ft. 0 in. Width: 1 ft. 0 in. – 2 ft. 0 in.

• Whole Plant Traits: Plant Type: Perennial Habit/Form: Clumping Erect Maintenance: Low Texture: Coarse Appendage: Prickles

• Cultural Conditions: Light: Full sun (6 or more hours of direct sunlight a day) Soil Texture: Loam (Silt) Sand Soil pH: Acid (<6.0) Alkaline (>8.0) Neutral (6.0-8.0) Soil Drainage: Good Drainage Occasionally Dry Very Dry Available Space To Plant: 12 inches-3 feet NC Region: Coastal Mountains Piedmont USDA Plant Hardiness Zone: 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b

• Fruit: Fruit Type: Schizocarp

• Flowers: Flower Color: Blue Gray/Silver Purple/Lavender Flower Inflorescence: Umbel Flower Value To Gardener: Good Cut Good Dried Long-lasting Showy Flower Bloom Time: Summer Flower Size: < 1 inch Flower Description: The long lasting flower head is a spherical-cylindrical umbel, 2 inches across packed with tiny, stemless, steel violet-blue flowers. A narrow, spiky collar of spiny, blue-green bracts surrounds the flower.

• Leaves: Leaf Color: Green Leaf Feel: Prickly Leaf Type: Simple Leaf Arrangement: Rosulate Leaf Shape: Elliptical Oblong Leaf Margin: Dentate Hairs Present: No Leaf Length: > 6 inches Leaf Description: Deeply toothed spiny basal elliptic to oblong with a cordate base form rosettes that reach 14″ wide.

• Stem: Stem Is Aromatic: No

• Landscape: Landscape Location: Container Patio Rock Wall Slope/Bank Small Space Landscape Theme: Butterfly Garden Cottage Garden Cutting Garden Drought Tolerant Garden Pollinator Garden Rock Garden Design Feature: Border Small groups Specimen Attracts: Bees Butterflies Resistance To Challenges: Deer Drought Dry Soil Poor Soil Rabbits Salt Problems: Spines/Thorns

Eryngium planum

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Eryngium – Blue Sea Holly – Water Wise Pollinator

Eryngium Blue Sea Holly is a unique variety for the garden. Its captivating blooms and foliage are a sight to see in bloom. Their leaves and blossoms have an unique look all their own and grow in a range of growing conditions. Their silvery-blue-green stems produce blue cones surrounded by silvery-blue bracts that bloom throughout the summer. These amazing plants are drought tolerant, deer and critter resistant, water-wise and attract butterflies like few other plants do. They are also perfect for cut and dried flowers.

Highlights

• Drought resistant
• Beautiful, showy blooms
• Grows well in containers, garden beds and borders
• Excellent for cut flower arrangements
• Easy to grow

Exposure:

Blooms:

Height:

Grows 24-36″ tall

Spacing/Depth:

Plant 18-24″ apart, 1-2″ deep

USDA Zones:

Grow as Perennial in zones 4-9. Grow as Annual elsewhere.

Growing Instructions

Plant Eryngium in the spring after all danger of frost has passed in a full sun location in moist but well draining soil. Soil preparation: The ideal soil is porous and drains well and yet still holds enough water for the roots. If your soil is heavy clay and drains slowly, or very sandy and does not hold water, add organic soil amendments (peat moss or ground bark). Spread a 3-4″ layer of soil amendment, add fertilizer and incorporate together into the soil to a depth of 10″. To plant: Dig a hole 1-2″ deep in a sunny (at least 6 hours of direct sun), well drained location. Place the Eryngium in hole with roots pointed down and space 18-24″ apart. Cover with soil and water. Mulch in extreme climates.

Care Tip

Deadhead spent flowers to encourage additional blooms.