Sea hollies resemble teasels, with compact heads of long-lasting, small blossoms surrounded by spiny petals that are actually leaves, or bracts. They belong to the carrot family, as evidenced by their thick taproots. The genus is an ancient Greek name for a species of Eryngium.
Description of sea holly: Sea hollies have simple, spiny-toothed leaves on stout stems from 2 to 6 feet tall, with clusters of teasel-like blossoms. They bloom in July and August. Sea holly ease of care: Easy.
How to grow sea holly: Sea hollies need full sun and a good, well-drained soil worked to sufficient depth for the growth of the taproots. Their deep roots make them difficult to transplant.
Propagating sea holly: By cuttings or by seed.
Uses for sea holly: For a bold stroke in the formal garden or a fascinating addition to the wild garden, sea hollies are a good choice. The flowers are not only excellent when cut, they are also valuable when dried for winter bouquets.
Sea holly related species: Eryngium alpinum grows to 2 feet tall with
11/4-inch long, silvery-blue flower heads. 'Donardt's Blue' bears blue flowers on 2-foot stems. Eryngium amethystinum is one of the best species, bearing small, blue flowers on plants to 3 feet high. Eryngium giganteum grows to 3 or 4 feet with silver-blue flower heads to 2 inches long. This species dies after flowering, although it usually produces abundant seedlings. Eryngium planum has many round, 1/2-inch long, blue flowers on 3-foot stems. It is not as pretty as the other species, making it better suited to a wild garden.
Scientific name for sea holly: Eryngitim species