Eryngium Planum ‘Blue’
Sea Holly has been grown in American gardens since the 1800s. Its an easy-to-grow fancy thistle with beautiful metallic, almost iridescent, bright blue, spiny flowers that sit atop 3 ft tall plants.
Sea Holly plants love sunshine and normal or sandy soil, and once established, they are extremely drought resistant. They make great specimens for low-water gardens. Seeds can be started directly outside in the spring after frost has passed. If the seeds are started indoors be sure to move the seedlings to their permanent location when they are still small because Eryngium plants have large taproots and won’t transplant well once mature.
Eryngium plants may or may not flower the first year from seed, but should come back with a vengeance in following years. They are valued by many for their prolonged bloom time. If you deadhead them they will keep putting out well into fall. Seeds will self-sow, but not to the point of becoming invasive. These plants attract bees and butterflies like crazy! This was our garden winner last year for ‘most visited’ by pollinators as well as having the ‘most diverse’ group of pollinators’ too.
Almost all Eryngium make excellent, long lasting cut flowers. Harvest them when the entire flower heads and bracts turn blue so the flowers will keep their beautiful blue color after drying.
Height: 3 ft
Zones: 4- 9