Allium 'Globemaster'

Planting Allium ‘Globemaster’

Allium ‘Globemaster’ is one of the most impressive ornamental onions, producing large, dense globe-shaped purple flower heads on tall, sturdy stems. It is perfect for adding bold structure and architectural interest to borders and planting schemes.

Choosing the right position

• Prefers full sun for best flowering
• Will tolerate light partial shade, though flowers may be smaller
• Ideal for borders, gravel gardens, and naturalistic planting
• Works well planted among perennials to disguise fading foliage
• Choose an open, well-drained position

Soil requirements

• Thrives in well-drained soil
• Prefers moderately fertile conditions
• Suitable for sandy, loamy, or chalky soils
• Does not tolerate heavy, waterlogged soil
• Improve drainage with grit if needed

How to plant bulbs

• Plant bulbs in autumn for late spring to early summer flowering
• Plant at a depth of around 15–20cm
• Space bulbs approximately 25–30cm apart
• Position bulbs with the pointed end facing upwards
• Backfill with soil and firm gently
• Water lightly after planting

Planting in containers

• Use a deep pot with good drainage holes
• Fill with a free-draining compost mix
• Plant bulbs at the same depth as in the ground
• Water lightly and place in a sunny position
• Ensure containers do not become waterlogged over winter

Ongoing Care and Maintenance

Allium ‘Globemaster’ is low maintenance and easy to grow, making it a reliable addition to any garden.

Watering

• Water lightly after planting
• Requires minimal watering once established
• Water during prolonged dry spells in spring
• Avoid overwatering, especially in winter
• Container-grown bulbs may need occasional watering

Feeding

• Apply a balanced fertiliser in early spring
• Alternatively, mulch with compost to improve soil fertility
• Avoid excessive feeding, which can reduce flower quality
• Generally thrives in average garden soil

Pruning and tidying

• Allow foliage to die back naturally after flowering
• This helps bulbs store energy for the following year
• Remove spent flower heads if desired
• Seed heads can be left for decorative effect
• Cut back dead stems once fully dried

Planting combinations

• Plant among later-emerging perennials to hide yellowing leaves
• Combine with grasses or hardy perennials for a natural look

Seasonal Care and Common Issues

With proper care, Allium ‘Globemaster’ will provide a spectacular and long-lasting display.

Seasonal performance

• Produces large, dense purple flower heads in late spring to early summer
• Flower heads can reach up to 20cm across
• Stems grow up to 80–100cm tall
• Long-lasting blooms and decorative seed heads
• Attractive to bees and pollinators

Winter care

• Fully hardy and tolerant of cold conditions
• No special winter protection required
• Ensure soil remains well-drained during winter
• Container plants should not sit in waterlogged compost

Common problems

• Bulb rot can occur in poorly drained soil
• Poor flowering may result from lack of sunlight
• Leaves may die back early, which is normal
• Generally pest and disease resistant
• Onion scent helps deter some pests

Allium ‘Globemaster’ is a bold and architectural bulb that adds height, structure, and striking colour to the garden. Its large, long-lasting flower heads make it a standout feature in any border. With a sunny position and well-drained soil, it will thrive and return reliably year after year.

We currently only deliver within the island of Ireland, other countries can be quoted for by contacting [email protected] or via telephone on 06964084
 

Standard Delivery is FREE on orders over €250*

All standard deliveries will be completed within 5-7 working days via Fastway Couriers, any delay to this delivery time, the customer will be notified by One of our staff.

The in-Store delivery charge will vary compared with online, in-store delivery charge is done on a case by case basis. 

* Only mainland Ireland addresses qualify for free delivery.
 

Live Plants Delivery

Our live plants are packed with care and diligence by our staff, our horticulturists review each plant before despatch to ensure quality is maintained.
Live Plant delivery charges are not calculated on weight but on the space required per package to ensure safe delivery, so delivery charges may vary as some plants require more space than others when packed.
All live plants are despatched within 3-5 working days where possible, our couriers aim to deliver within 48 hours of despatch from our Garden Centre to allow the plant to arrive in healthy condition.
 

Click & Collect

Can’t wait for delivery? Why not try our FREE Click & Collect service? Simply make your purchase online and collect it from our store located in Croagh Co. Limerick. Our staff will contact you by phone when your order is ready for collection (Please allow 24 hours minimum). When collecting your item, call the store on 069-64084. We will then load into your car as required. This service is available in-store 9am – 6pm Monday – Saturday (No collections on Sundays)

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If you have any further questions about the online order payment please contact us via ­069 640 84 or mail.