We're offering you a 8 or 32 Allium Big Impact Mixed Bulbs for £6.99, saving you up to 30% off Thompson and Morgan's's price of £9.99 (correct as of 26.08.2025).

Allium 'Big Impact Mix' – Tall, Hardy Perennial Bulbs

Add bold structure and vibrant colour to your garden with Allium 'Big Impact Mix'. These ornamental onions produce impressive, globe-shaped flower heads in a stunning palette of purples, pinks, and whites. Each bulb develops into a tall stem reaching up to 90cm (35"), perfect for creating vertical interest in borders or mixed beds.

• Botanical Group: Allium (Ornamental Onion) – part of the Amaryllidaceae family.
• Mature Size: Height up to 90cm (35"), spread approx. 15cm (6").
• Flowering Period: Late spring through early summer (typically May–June in the UK).
• Hardiness: Fully hardy perennial suitable for UK climates.

Growing Guide

• Planting Time: Plant bulbs from September to November before the first frost.
• Soil Preference: Prefers well-drained, fertile soil; avoid waterlogged sites.
• Light Requirements: Thrives best in full sun but will tolerate light shade.
• Planting Depth & Spacing: Plant bulbs 10–15cm deep and space about 15cm apart.
• Caring Tips: Water well after planting; allow foliage to die back naturally after flowering to feed the bulb for next year’s display.
• Pest & Disease Resistance: Generally resistant to deer and rabbits; low maintenance once established.

Design & Companion Planting Ideas

• Create impact by planting in groups or drifts for a massed effect.
• Pair with late-spring perennials like Nepeta, Salvia, or hardy Geraniums for complementary colour and texture.
• The architectural seed heads look striking among ornamental grasses or left standing over winter for added structure.

FAQs

• When is the best time to plant Allium bulbs?
  The ideal time is autumn, from September to November, before the ground freezes.
• How long do Alliums take to flower?
  Buds emerge in late spring, typically flowering within the first season after planting if planted at the correct time.
• Do Alliums need special care?
  No special care required—just plant in well-drained soil and full sun. Allow leaves to die back naturally after blooming for best results next year.