Eryngium x zabelii 'Big Blue'Sea Holly

Eryngium x zabelii Big Blue is one of the largest and most vibrant blue-flowered varieties of eryngium, truly living up to its name. In the early summer months, it forms low clumps of grey-green, finely divided leaves with a soft, spiny texture, remaining understated as the garden begins to grow. However, come August, the plant undergoes a dramatic transformation. Sturdy, steel-blue stems emerge from the foliage, branching into striking thistle-like flowers with a unique architectural design. Each bloom features a central cone encircled by delicate, slender bracts, creating a stunning contrast of intense metallic-blue colour. The flowers are especially captivating during the evening when they shimmer in low light. The flowerheads stay intact through the winter, offering ongoing interest to the garden, especially when dusted with frost or dew. Once established, Big Blue is drought-tolerant and thrives in poor, well-drained soils. It is ideal for dry, sunny Mediterranean-style borders or gravel gardens, where its bold structure stands out among softer, mound-forming plants. Its vibrant flowers are highly attractive to bees and butterflies. Awarded the RHS Garden Merit Award for its exceptional qualities. Height: 70cm (28in). Spread: 60cm (24in). As plant size varies with the seasons, we list by pot size rather than a fixed height and spread. Images shown are for reference only, as the plant’s growth will differ depending on the time of year. One of the largest flowered and most blue of all eryngiums, with branching stems carrying large thistly, steely-blue flowers, each with a prominent ruff, from August onwards. Grow sea holly plants on light, well drained soil in full sun. Eryngium plants particularly dislike cold, wet soil in winter which may cause the crown to rot. If planting on heavy soils, dig in plenty of coarse grit to improve drainage prior to planting.