Eryngium alpinum (S)
Hardy in Zones 5-8.
Sea Hollies thrive in full sun and average, well-drained soil. They tolerate heat and drought and poor soil, but require excellent drainage, especially in winter. They have deep taproots and resent being disturbed so select a permanent location. Blooms from midsummer to fall. Often self sows and small seedlings can be replanted at any time.
Plant two inches deep and space 1-2 feet apart.
