Eryngium planum Seeds – Sea Holly Ornamental Garden Flowers

Sea Holly (Eryngium planum) is a distinctive perennial flowering plant known for its steel-blue flower heads, spiky bracts, and upright stems. A member of the Apiaceae family, it brings a striking architectural appearance to garden landscapes. Its unusual flower shapes and blue tones create an attractive contrast with green foliage and other flowering plants.

This hardy perennial is well suited to sunny borders, gravel gardens, and naturalistic planting schemes. Sea Holly develops a branching growth habit and produces flower heads that can retain their shape as they mature. Its blooms also attract bees and other visiting pollinators, making it a useful addition to pollinator-friendly gardens.

• Common Name: Sea Holly, Blue Sea Holly
• Botanical Name: Eryngium planum
• Plant Family: Apiaceae
• Plant Type: Perennial flowering plant
• Foliage: Green to silvery-green leaves
• Flowers: Small blue flowers grouped into rounded heads with spiky bracts
• Growth Habit: Upright, branching stems
• Distinctive Feature: Steel-blue flower heads with decorative, spiny bracts
• Garden Use: Perennial borders, gravel gardens, pollinator-friendly spaces, and floral arrangements

• Light: Choose a location with full sun.
• Soil: Use well-draining soil and avoid areas where water collects.
• Watering: Water regularly while seedlings establish. Once mature, the plant generally tolerates relatively dry conditions.
• Seed Starting: Sow seeds in a suitable seed-starting medium and follow the supplier’s instructions for sowing depth and germination conditions. Germination may be variable.
• Transplanting: Move established seedlings outdoors when growing conditions are suitable, taking care around the roots.
• Spacing: Provide sufficient room for mature growth and branching stems.
• Container Growing: Use a deep pot with drainage holes and a well-draining growing medium.
• General Care: Avoid overwatering and provide good air circulation around the foliage.

Sea Holly adds distinctive color and structure to sunny garden beds and perennial borders. Its blue flower heads pair well with ornamental grasses and other sun-loving plants. The flowers can attract pollinators, and mature stems may also be used in fresh or dried floral arrangements.

Growth and flowering depend on local climate, sunlight, soil conditions, and care. For best results, choose a sunny site with well-drained soil.