Allium 'Giganteum'

1 bulb
£5.99
£5.99 each
5 bulbs
£23.99
£4.80 each
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Order today, receive in August/September

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Our "Bloom or Bust" Promise

This is the original giant that started it all! When Victorian plant hunters first saw it, they were so amazed by its size they simply named it 'giganteum' – Latin for 'giant'!

The "Giant Allium" is the species that started the craze for these incredible plants. Allium giganteum was one of the first giant ornamental onions to be introduced to European gardens from its native Central Asia. It produces wonderful 6-inch globes of bright lilac-purple flowers on towering stems that can easily reach 5 feet. While newer hybrids may be larger, giganteum has a classic, reliable charm and a slightly more open flower structure that gives it a softer, more airy feel than its dense hybrid cousins. It is a true garden heirloom and a must-have for creating that classic, vertical cottage garden look.

Botanical name Allium giganteum
Flower colour Lilac-purple
Bulb size 20/+ cm
Established height 120-150 cm
Established spread 20-30 cm
Plant spacing 7-10 bulbs per m²
Leaf colour Grey-green
Habit Upright
Life cycle Perennial
Hardiness Fully hardy
Years to establish 1st year
Sunlight Full sun
Position Sheltered
Suitable for Borders, Gravel gardens
Soil acidity Any
Soil moisture Free draining
Soil type Loam, Sandy, Chalky
RHS Award (AGM) Yes
Growing skill Easy to grow
Pollinator-friendly Yes
Deer resistant Yes

Where to Plant:

Choose a location that receives at least six hours of direct sunlight per day. Well-drained soil is essential, as these large bulbs will rot in soggy ground. They are perfect for adding height and structure to the back or middle of perennial borders and make stunning, long-lasting cut flowers.

How to Plant:

In the autumn, plant each bulb with the pointed tip facing upwards, about 15-20cm (6-8 inches) deep. This depth is crucial to help support their tall, heavy flower heads. Space them at least 20-30cm (8-12 inches) apart to give them room. For a powerful visual statement, plant in bold drifts of five or more bulbs. Water them once after planting to help settle the soil.

Aftercare:

Once the impressive flower globes fade, allow the foliage to die back and turn yellow naturally. Do not cut it down while it is still green. This is the most important step for ensuring a repeat performance, as it allows the plant to store energy in the bulb for next year's bloom. The dried seed heads can be left for extended structural interest or removed by snipping the stalk at the base.

Planting and Flowering Calendar

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Key Features

Packed in paper

Packed peat-free

Great for Shade

Attracts wildlife

Drought tolerant

Low maintenance

RHS Award (AGM)

Rodent resistant

Allium 'Giganteum' - Harding & Bloom

Allium 'Giganteum'

£5.99

£5.99

The Finest Bulbs

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Kind Words from Our Gardeners

Arrived quickly and well-packaged. Planted them in some pots on the patio and they all came up. Look beautiful. Thank you!

Careane Wallace

Oxfordshire, UK

The bulbs arrived beautifully packaged and you could just tell they were excellent quality. We had the most wonderful display of daffodils this spring on our patio. Simply stunning. Will definitely be ordering again

David P

Kent, UK

I ordered the mixed hyacinth collection and the scent in my garden this April was absolutely heavenly. Every single bulb produced a strong, beautiful flower and the colours were stunning together. A fantastic purchase, I'll be back for more next year!

Eleanor R

Somerset