Eryngium agavifolium

Eryngium agavifolium or Agave-leaved Sea Holly is a very unique perennial. Its egg-shaped flowers have incomparable shades: initially light green at the beginning of their July flowering, they then slightly whiten and end the summer in a subtle blueish grey. These are highlighted by a cluster of long green, thorny, and evergreen leaves under mild climates. The combination is perfect to structure exotic and wild gardens.

Like most Eryngiums, E. agavifolium thrives in rather poor and well-drained soils. It appreciates full sun, is suitable for rockeries, and does not tolerate winter waterlogging.  However, it can withstand temperatures close to -10°C (14°F). Its upright habit, as well as its bristly appearance, are often used to structure flower beds and create contrast with softer and gentler neighbouring plants. It can even remain in place in autumn (drying on the stem) to occupy space and attract birds. However, do not hesitate to cut it and include it in dried bouquets, as it is perfectly suited for this purpose.

The leaves of the Agave-leaved Sea Holly sets it apart from other Eryngium. These are long, 40 cm (16in), sword-shaped, shiny green, and have spiny margins. They are evergreen if the cold is not too intense in your region, and as its name suggests, they resemble Agave leaves. They form a large rosette, from which emerge upright stems carrying ovoid flowers, 5 cm (2in) in size, highlighted by a star-shaped bract. This bract reduces as the head grows. If your Eryngium is happy, it can reach a height of 150 cm (59in).

An essential choice if you want an exotic touch in your garden, Eryngium agavifolium is welcome in all gardens. Its long shiny leaves attract light, and its numerous conical flowers blend in with all the summer blooms. It works well between Gaura and Gypsophila, and completes the silver range of Stachys, Cerastiums, and Artemisias.