Allium (Ornamental)

Allium spp.

Ornamental alliums are among the most architectural and eye-catching bulbs for UK gardens, producing spherical heads of tiny flowers on tall, straight stems from late May to July. They range from the spectacular giant alliums — A. giganteum with dense, softball-sized purple heads on 1.5m stems — to more delicate species like A. cristophii with large, open, metallic-purple globes, and A. sphaerocephalon with small, egg-shaped, rich burgundy heads. They create magical effects rising through other planting and combine beautifully with roses, lavender, grasses, and herbaceous perennials. Plant bulbs in autumn, 3–4 times the bulb's depth in well-drained soil and full sun. They tolerate most soils but dislike heavy, waterlogged clay. Once established, they're drought-tolerant and increase year after year. The dried seed heads are as decorative as the flowers — leave them standing through summer and autumn. 'Purple Sensation' is the most versatile and best value allium — naturalising freely and flowering reliably every year. For drama, nothing beats A. giganteum or its hybrid 'Globemaster' with enormous 20cm purple spheres. A. 'Mount Everest' provides a stunning pure white alternative.

Plan where to grow Allium (Ornamental) using our vegetable garden planner.