Seaholly 'Tetra Petra'

This striking perennial produces steel-blue, globe-shaped flower heads atop spiny, deeply textured foliage, creating a dramatic and sculptural effect in summer gardens. Flowering throughout the season, it adds long-lasting colour, structure, and a touch of architectural elegance to borders, rockeries, and mixed plantings.

Its upright, clumping habit provides height and form, making it ideal for adding contrast to softer perennials and grasses. Thriving in well-drained soil, it prefers full sun and tolerates dry, exposed conditions, making it a resilient and low-maintenance choice for sunny gardens.

The bold, metallic flowers attract bees, butterflies, and other pollinators, supporting garden biodiversity while creating a visual focal point. It also works beautifully as a dried or fresh cut flower, retaining its striking colour and form.

Perfect for gardeners seeking texture, drama, and long-lasting summer interest, this plant combines resilience, architectural beauty, and ecological value, making it a standout addition to contemporary, cottage, or naturalistic garden designs.