Eryngium, commonly called sea holly, might appear anything but inviting at first, but on closer inspection you’ll realize there is nothing to be fearful of. I found this spiky flower in a friend’s birthday fragrance and have been a fan ever since. Sea holly has a long history of cultivation, and recent trending in foraged bouquets and crazy gardens has given it new popularity. Upright, thistlelike along with a vivid shade of blue tip to stem, this is a flower to notice — both in hand and in the garden.
Hailing from Northern Africa, Europe and even Asia, sea holly thrives in several climates.
Jess Knowles
Botanical name: Eryngium spp
Common title: Sea holly, Eryngo
USDA zones: 5 to 11, based on species
Water requirement: Low
Light requirement: Full sun
Mature size: 2 to 6 feet tall, depending on species
Benefits and tolerances: Plants attract butterflies and bees; drought and coastal tolerant, depending upon species
Shown here: Eryngium alpinum ‘Blue Star’, zones 5 to 9
Svein Erik Larsen
Distinguishing attributes. Frequently mistaken for thistle, sea holly is recognized by its spiny leaves and cone-shape flowers. Sea holly blooms in the summer and even into fall, producing a multitude of vertical weathered flowers in white, violet, silver, green and every colour in between.
Erect stalks of comparable colors continue to grow and thrive for the rest of the year. Leaf types vary from long, narrow spikes to foliage with large lobes.
Shown here: Eryngium dilatatum ‘Azulillo’
Glenna Partridge Garden Design
The best way to use it. Peeking above the surrounding foliage, sea holly’s form divides surrounding foliage and generates vertical attention, while its colour is in tune with the masses of purple, light green and cream. Plant sea holly in a stone garden, where its taste for well-drained and mild soil will come in handy along with its cool-blue foliage will match natural stone colors.
Sea holly is much more commonly seen in floral arrangements. Whether used as the primary flower or a fragrance accent, they’re long lasting when cut — both dried and fresh. Cut stems when flowers are half open for best results.
Planting notes. Native into a wide array of climates and growing conditions, sea holly is really tolerant and able to develop in a vast array of environments. Provide ample sunlight and their foliage and flower hues will deepen and become more lively.
Sea holly prefers mild, well-drained dirt — a few species are partial to sandy lands, while some prefer soil that preserves a certain quantity of moisture. The one feature that all sea hollies share is just one deep taproot. This makes them more resistant to drought but far more challenging to transplant, therefore transplanting is not recommended.
Shown here: Eryngium bourgatii, zones 5 to 9
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