Sea holly Blue Star

This plant requires, above all, well-drained, non-waterlogged soil. It will grow well even in poorer, stony, or sandy soils. It is important that water does not stand at the roots, especially in winter, as the roots could rot. Heavy and clayey soils must be improved with drainage (gravel, sand) before planting.

The 'Blue Star' sea holly is a sun lover, so choose a fully sunny location for it. It does not do well in the shade—in the shade, it becomes leggy, blooms less, and loses its typical steel-blue color. It is an ideal choice for:

• Gravel beds
• Rock gardens
• Steppe plantings
• Sunny perennial beds

Container growing is possible, but you must choose a sufficiently deep pot, as Eryngium develops a long taproot. Ensure perfect drainage at the bottom of the container so the roots do not sit in water, and use a substrate mixed with sand or gravel.

This variety grows to a height of 40 to 70 cm. It is therefore ideal for the middle sections of perennial beds, where it creates a striking architectural element without shading the plants behind it. Thanks to its sturdy stems, it does not require support.

Yes, Eryngium 'Blue Star' is truly a magnet for pollinators (🐝). Its flowers produce nectar that attracts bees, bumblebees, and butterflies. By planting this, you will significantly support biodiversity in your garden.

Yes, sea holly is a fully hardy perennial. It is classified in zone 5a, which means it can withstand frosts ranging from -28.9 °C to -26.1 °C. It handles winter in our climate without any problems, provided it is planted in well-drained soil. Winter moisture is a greater danger to it than frost.

Yes, Eryngium is not poisonous and is even considered an edible plant, although it is primarily grown for ornamental purposes today. However, its prickly bracts can be unpleasant to touch for small children or pets, so it is best to plant it in areas where accidental contact with the thorns is unlikely.

Definitely! Eryngium is highly valued in floristry. You can use it:

• In fresh bouquets: It lasts a long time in a vase and adds a firm structure to arrangements.
• For drying: It is one of the best plants for dried decorations. The flowers retain their shape and blue color even after drying. To dry, cut fully developed flowers and hang them upside down in a dark, airy place.

Yes, Eryngium can self-seed in the garden. If you do not want it to spread, remove the faded flower heads before the seeds ripen. However, natural self-seeding can eventually create beautiful, natural-looking clusters.

The above-ground part of the plant is very healthy and usually does not suffer from diseases or pests. However, there is one risk underground – voles. Unfortunately, they find Eryngium roots very tasty. If you have issues with voles in your garden, we recommend planting them in wire baskets.

The most common cause of Eryngium dying in winter is not frost, but winter moisture. If the soil is heavy and retains water, the root crown and roots of the plant will rot. Prevention involves planting in well-draining soil mixed with gravel or in raised areas (rock gardens).

The 'Blue Star' sea holly blooms in summer, specifically in the months of June, July, and August. Its inflorescence is cylindrical, surrounded by a striking collar of finely divided bracts. The color is fascinating—shifting from silvery to an intense indigo blue with a metallic sheen. This color develops fully in a sunny location.