Sea Holly Blue flowers seed (Eryngium Planum) perennial
Unique and stately, Eryngium Planum, commonly called Sea Holly, has been grown from flower seeds in America since the 1800's. It can be propagated by division, flower seed and root cuttings. Almost all Eryngium make excellent cut flowers as well as flowers used for drying. The flowers keep their beautiful blue color after drying indoors. Harvest flowers when the entire flower heads and bracts turn blue.
Eryngium Sea Holly self-sows readily by dropping its flower seeds on the ground, but it is not invasive. If the Sea Holly seeds are started indoors, transplant the seedlings where you want them to grow when they are quite small. The Eryngium plants have taproots, so they won't transplant well once mature. Sea Holly plants attract bees and butterflies, and they are a great plant for a low water garden. Eryngium seeds can be started directly outside in the spring after frost season has passed.
USDA Zones: 4 - 9
Height: 28 inches
Bloom Season: Summer to fall
Bloom Color: Blue
Environment: Full sun to partial shade
Soil Type: Well-drained soils, pH 6.8 - 7.2
Temperature: 64 to 72F for the first 2-4 weeks. After this period, the sowing must be kept at a cold temperature between 25 and 39F for another 4 - 6 weeks
Average Germ Time: 28 - 56 days
Light Required: No
Depth: Surface sow seed and press tightly in to soil
Sowing Rate: 4 - 5 seeds per plant
Moisture: Keep seeds moist until germination
Plant Spacing: 24 inches