Beautiful Blue Sea Holly
(Editor's Note: This article was originally published on February 18, 2010. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)
A perennial wildflower native to the Caucasus and Iran, Eryngium comprises about nineteen known species, but the most common are Common sea holly (E. maritimum), Rattlesnake Master (E. yuccifolium), Alpine sea holly (E. alpinum), Giant sea holly (E. gigantium), Mediterranean sea holly (E. bourgatii), Flat sea holly (E. planum), and Zabel eryngo (E x zabelii). Amethyst sea holly (Eryngium amethystinum), shown at right, is striking with its purple-blue heads and stems.
A charming story tells of noted British garden enthusiast, Ellen Wilmott, being so enamored of Sea Holly that she always kept some seeds in her pocket. If she chanced upon a garden she considered to be "boring", she'd scatter a few sea holly seeds and move on. When the seeds sprouted in all the places Miss Wilmott had visited, the plant became affectionately known as "Miss Wilmott's Ghost."
Each species has its own distinct bracts and foliage, from stickery and spiky bracts to heart-shaped or holly-shaped leaves, but all species have a lovely gray or green or silvery foliage and stems. From as small as 12 inches tall to those reaching 4', Eryngium can fit into almost any garden space. But the beauty of this plant is not just in its striking contrast to the plants around it, but the ease with which it can be grown and maintained.
Average well-drained soil in full sun is all it needs, and it will even tolerate sand and gravel. Seeds can be sown outdoors in the fall, or indoors in winter; however, winter sowed seed flats will have to be refrigerated for 4 to 6 weeks before allowing the seeds to germinate. Additionally, plants started from seed may not bloom the first year. Plants are often available from mail-order catalogs and some garden centers, and Dave's Garden Plant Traders usually has several for trade. Literature cautions that the plant does not transplant well, so be sure of the location before sowing seed or setting out plants. Bloom begins in July and continues profusely through September or October, depending on region. The U.S. cultivars do well in zones 5 to 9.
Interesting Facts and Lore About Sea Holly
- In the 17th and 18th centuries, herbalists candied the roots and touted them as an aphrodisiac.
- The extensive root system of sea holly is useful in erosion control.
- The root is used as a diuretic, expectorant, stimulant, and tonic in today's array of natural remedies.
- Flowers and foliage are excellent for drying and in floral arrangements.
- Leaves and roots are edible.
- Deer dislike sea holly.
Sources for Plants and/or Seed
Photo Credit: Teun Spaans, Wikimedia GNU Free Documentation License, 2007