Allium Globemaster

One of the most spectacular ornamental alliums available, Allium ‘Globemaster’ produces enormous globe-shaped flower heads packed with hundreds of tightly clustered violet-purple star-shaped florets.

Held on tall, sturdy stems, the huge blooms create a bold architectural statement in the garden and can remain attractive for many weeks, gradually developing into decorative seed heads that continue to provide structure long after flowering.

Introduced in the mid-20th century as a hybrid between several Central Asian allium species, ‘Globemaster’ quickly became one of the most celebrated ornamental alliums thanks to its exceptionally large flower heads and reliable garden performance.

Perfect for sunny borders, gravel gardens and naturalistic planting schemes, the flowers rise dramatically above surrounding perennials and ornamental grasses, bringing height, texture and elegance to the early summer garden.

Highly attractive to bees and pollinators, this award-winning variety is also excellent for cutting and drying, making it as valuable indoors as it is in the garden.

Easy to grow and wonderfully long-lasting, Allium ‘Globemaster’ is a true statement plant for any sunny border.

RHS Award of Garden Merit.

Allium Globemaster has been awarded the RHS Award of Garden Merit because it has proved to be reliable in appropriate conditions and a good performing plant. 

Planting Instructions

When to Plant:

Plant Allium bulbs in autumn (September–November) before the ground freezes. This allows roots to establish for strong flowering the following season.

Where to Plant:
Choose a sunny position with well-drained soil. Alliums are ideal for borders, gravel gardens and naturalistic planting schemes. Avoid areas where soil remains wet over winter.

How to Plant:

• Depth: Plant bulbs about 15–20 cm (6–8 inches) deep.
• Spacing: Space bulbs about 20–25 cm (8–10 inches) apart.
• Soil Prep: Improve soil with compost. In heavier soils, add grit or sharp sand to improve drainage.

Watering:
Water after planting. Once established, Alliums require very little additional watering unless conditions are particularly dry.

Aftercare Tips:

• Allow foliage to die back naturally after flowering to feed the bulb.
• Leave seed heads standing for long-lasting architectural interest.
• Avoid excessive moisture in winter to prevent bulb rot.

Top Tip:
Plant amongst ornamental grasses or flowing perennials to highlight the huge flower heads and create a spectacular naturalistic display.

Plant Details

Flowering Period:
June - July (depending on season and conditions)

Height:
32–40" (80–100cm) (approx.)

Position:
Full sun

Hardy Perennial