Product description
Allium 'Globemaster', commonly known as Ornamental Onion, is a striking perennial that adds architectural interest to gardens with its impressive, spherical clusters of violet-purple flowers. Each bloom, composed of hundreds of star-shaped florets, measures up to 15 cm across, creating a dramatic focal point from May to June. The tall, sturdy stems rise above a basal rosette of strap-shaped, grey-green leaves, making this variety a standout in borders and flower beds. Its vibrant colour and striking form make it a popular choice for contemporary and traditional garden designs alike.
Thriving in well-drained soil under full sun, 'Globemaster' is an easy-to-grow perennial suited to UK gardens. Its hardy nature allows it to withstand various conditions, and once established, it is drought-tolerant and requires minimal care. Bulbs should be planted in early to mid-autumn at a depth of 10-15 cm, ensuring they have good drainage to prevent rot. Removing faded flower heads helps maintain the plant’s neat appearance and prevents excessive self-seeding. With proper care, this allium will return year after year, adding height and colour to garden displays.
Beyond its stunning floral display, Allium 'Globemaster' is highly attractive to pollinators, drawing bees and butterflies into the garden. Its dried seedheads also provide interest into autumn, adding textural appeal even after the flowers have faded. Ideal for cutting, these blooms make an excellent addition to fresh or dried floral arrangements. Whether planted in garden borders, rockeries, or large patio containers, this variety ensures a long-lasting visual impact and enhances biodiversity within outdoor spaces.
Please Note: Images are for illustrative purposes only and designed to be a representation of the item(s) being sold. Depending on seasonality, deciduous plants may be supplied in their dormant state and without leaves. Plants may also be pruned back, lower than stated heights, to encourage new growth.
Garden Plant Size Guide
Plants in larger pots can be multiple years older than their smaller counterparts with more mature root systems and foliage. This makes them able to thrive as a full size plant in your garden quicker than smaller alternatives.
The most common size of pot that garden plants come in are 9cm/1L/3L/5L this is in reference to the diameter at the top of the pot.
9cm potted plants still remain the most popular cost effective option though, they just may take a little patience to allow them to grow into full maturity once planted in your garden.
Plant specs, care guide & tips
Key features
Specifications
When to plant
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
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Planting and period of interest times are general guidelines and may vary based on your location and conditions. For best results, consult local gardening resources.
Instructions
Top Tip
Plant alliums alongside other leafy plants that can hide the faded allium foliage after flowering.
How to Water
Water alliums regularly until established then only as required during dry spells.
How to Plant
Alliums thrive in full sun in well-drained soil and prefer a sheltered site where their flower spikes won’t get blown over.