Allium Bulbs
Allium flower bulbs will be available to order from spring 2025 for delivery and planting in autumn 2025.
For spring planting, check out our wildflower bulbs ‘In The Green’ which are available to order now for planting from January to March.
Creating the most magnificent display, Alliums come in all sorts of shapes and sizes. Although a firm favourite with avid gardeners, these are most popular with bees, butterflies and insects who cannot resist those nectar-rich flowers. Gigantic alliums such as Giganteum will create drama planted in borders, whilst Wild Garlic will fill the air with its scent after those early spring showers.
Like everything we supply here at Boston Seeds, we pride ourselves on supplying professional quality - and for flower bulbs, that means BIG! Our bigger bulbs produce bigger, better and bolder flowers. Choose from our exciting range of varieties - allium surprise bulb collection, old favourites, garden classics as well as striking new lines for 2024.
Don't hesitate to get in touch to speak to one of our experts or request a catalogue to view our full range. Ordering regularly or looking for large volumes? Click here to apply for a trade account today - we review all applications within one working day.
Producing large spherical flower heads, that are a fantastic lilac purple. These are a must to attract bees and other pollinators into your garden, whilst also having a light fragrance they are suitable for pots or creating structure in your borders.
- Height (cm): 70cm
- Bulb Size (cm): 10 / 12cm
- Blooms: May/June
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Contains a minimum of 4 varieties of alliums ranging in height, shapes and colours to create bold features in the garden or a great floral display as dried flowers. These magnificent allium flower heads supply a real feast of nectar for pollinating insects.
- Height (cm): 100 - 120cm
- Bulb Size (cm): 6 - 20cm
- Blooms: May- June
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A structural masterpiece! This stunning giant allium will add height to your borders as well as attracting an array of bees, butterflies and other pollinators to fill your garden with early summer flurry. Ideal for use as dried cut flowers in your home once they have finished flowering.
- Height (cm): 130cm
- Bulb Size (cm): 20+ cm
- Blooms: June/ July
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Looking stunning when planted in a border amongst contrasting ornamental grasses and other foliage, these giant deep purple spherical flowers appear on a tall upright stem. This variety is also popular with bees and butterflies providing a valuable source of nectar.
- Height (cm): 75cm
- Bulb Size (cm): 7 / 8cm
- Blooms: May/June
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Plants for Pollinators highlights plants selected by the RHS as scientifically proven to tackle the declines in bees, butterflies and other pollinators.
A wild relative of chives, Wild Garlic (or Ramsons) grows from a small bulb and often spreads to form large clumps. It can be found in damp woods, scrub, hedges and on shady banks, where its garlicky aroma will fill the air. The leaves are edible but have a surprisingly mild flavour.
- This is an excellent plant for ground cover in a wet corner of the garden.
- These wild garlic bulbs are UK native
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Our flowering bulb fertiliser has been specifically designed to help your spring-flowering bulbs flower to their full potential. Whether you are establishing in pots or containers, sprinkle a small amount into each hole prior to planting your bulbs. Also suitable for use in early spring to encourage your bulbs to flower well in the following season.
- Tailored to give your bulbs all the nutrients they need
- Can be mixed with compost or Bulb Fibre
- NPK - 12.11.18 + MgO
- Recommended coverage: 5kg per 200sqm. Apply at 25g/sqm
- Not suitable for use with Wildflower Bulbs
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Specifically designed to help bulbs establish in pots and borders, without the risk of the bulbs rotting, providing an open and free-draining soil structure.
- Ideal for planting with Narcissi, Crocus, Hyacinths and other spring-flowering bulbs
- Universal bulb planting fibre
- 500gm bag - This pack is sufficient for 3 x 1-litre pots
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Making bulb planting easier, quicker and cleaner, our bulb planter is the ideal tool for helping you plant your spring-flowering bulbs.
- Made of high quality steel
- Automatic release on handle
- Duroplast coating - impact, elastic, abrasion, and corrosion - resistant
- Depth Scale
Our bulb planting essentials pack has been put together for the ease of ensuring quick planting and a great display. The bulb planter will help you plant the bulbs with ease whilst the fibre will ensure the bulbs do not rot when planted into pots or containers. Using the bulb fertiliser will ensure your bulbs have all the nutrients they need whilst establishing.
- 1 x Bulb Fibre
- 1 x Bulb Planter
- 1 x Bulb Fertiliser
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Easy to grow, later flowering alliums these deep aqua blue blooms will add a boost of colour and sweet scent to your beds' borders or pots. They can be in partial shade or full sun and prefer well-drained soils.
- Height (cm): 60cm
- Bulb Size (cm): 4 / 5cm
- Blooms: June/July
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Deep blue flower heads that flower later in the allium season, a great addition to extend your flowering borders.
- Height (cm): 40cm
- Bulb Size (cm): 5/+cm
- Blooms: June/July
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With two tone petals, these delicate alliums are great for attracting bees and butterflies into your garden. Flowering later in the spring to add longevity to your flowering borders.
- Height (cm): 30cm
- Bulb Size (cm): 4/5 cm
- Blooms: May/June
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Early summer flowering, these beautifully delicate flowers will sway in the summer breeze. Attracting bees and butterflies, whilst also being deer proof and suitable for naturalising, they are a multi purpose/ value for money variety.
- Height (cm): 45cm
- Bulb Size (cm): I
- Blooms: June/ July
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A more unusual Allium, the Christophii form the classic globe flower head but produce multiple starburst flowers per stem. Those early summer dews bring these blooms alive with a shimmer of silver, these lilac flowers come into their own.
- Height (cm): 40cm
- Bulb Size (cm): 10 / 12cm
- Blooms: June
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These small dainty pure white blooms have multiple flowers per stem. These are a smaller allium and ideal for adding extra colour into your borders yet also good for pots and cut flowers.
- Height (cm): 40cm
- Bulb Size (cm): 5+ cm
- Blooms: June
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Our best value selection for adding beautiful giant alliums into your garden displays. These structural impressive flowers will add height and interest to borders and landscaped areas whilst also drawing in a flurry of bees, butterflies and other pollinating insects. This mixture will contain equal quantities of the following:
- Ambassador
- Pink Jewel
- Red Mohican
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Large violet-purple globes, that open up to 6 inches across, these giant alliums add structure and focus to borders and beds along with a great talking point for garden parties.
- Height (cm): 150cm
- Bulb Size (cm): 20cm+
- Blooms: June/July
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Standing over a meter high these enormous lilac/ purple globe heads can be up to 15cm across. These make great cut flowers and will also spread over time to create a dense display of tall blooms.
- Height (cm): 120cm
- Bulb Size (cm): 20cm+
- Blooms: June
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Producing several small star-like flowers on each stem, the flower heads open to reveal beautiful crisp white flowers with purple centres. Suitable for borders, these also look stunning as part of a bulb lasagne in pots.
- Height (cm): 40cm
- Bulb Size (cm): 6+ cm
- Blooms: June/ July
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The ultimate tool for planting quickly and easily your plants and bulbs. A quality solid ash handle securely fitted to a stainless steel blade, the traditional deisgn is ideal to assist in planting your plants and bulbs into beds, borders and grassland.
- Made of high quality polished stainless steel
- Ash handle - sourced from a sustainable source
- Soft leather strap - ideal to hang up
A firm favourite with the bees, these golden yellow blooms appear with multiple flowers on each stem. Excelling in woodland areas they are a fast-growing hardy allium perfect for pots, beds and borders.
- Height (cm): 25cm
- Bulb Size (cm): 5+ cm
- Blooms: June/ July
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Exuberant pure snowy white gigantic blooms, the Mount Everest Alliums are a real showpiece and head-turner. Suitable for adding height and structure into borders and beds.
- Height (cm): 120cm
- Bulb Size (cm): 20+cm
- Blooms: June
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Planted in mass, these dainty little alliums have delicate clusters of pure white flowers appearing on one stem. They will appear in late spring and create swathes of white blooms that can also be used for cut flowers.
- Height (cm): 40cm
- Bulb Size (cm): 4+ cm
- Blooms: April/ May
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Also known as Honey Lily or Siculum, this unusual flower has long hanging bell-shaped flowers, that is a creamy green with tinges of pink on the petals. The decorative seed heads will appear in late summer.
- Height (cm): 60cm
- Bulb Size (cm): 8 / 10cm
- Blooms: May/June
This item is currently unavailable
Alliums: Advice On How To Grow Them (And Why!)
If you’ll pardon the pun, this bulb flower has a real way of growing on you; it produces medium-to-tall upright stalks ending in a bold globe of fluffy-looking florets in a rich violet colour (though several species have lighter lilac petals). These punchy, purple pom-poms have a real way of drawing the eye - as such, you’re best scattering them evenly throughout a sunny border or a tall, grassy meadow. They’re also excellent cut flowers!
Fun Facts
The ornamental allium symbolises unity and patience. Fitting, as it grows dozens of florets in one bulb. In fact, the word “onion” is derived from the latin word unio, as in union!
There aren’t many myths surrounding onions, as you may expect from a plant most commonly seen in the kitchen; however, there are some myths linking them to the magic of tears and the importance of emotional release.
How to grow
Alliums are best planted early-to-mid autumn, and typically flower from May to June. They require well-drained soil and plenty of sunlight - be wary of cold or wet conditions where the bulbs may rot. Their tall, upright stems also require protection from the wind.
Smaller species of allium should be planted roughly 10cm apart; taller species require 20cm between each bulb. Alternatively, they can be planted in containers.
Alliums are tolerant to drought and dislike being watered in the summer. Alliums grown in containers will need regular watering, but take care that they don’t get too damp.
Alliums have sparse foliage at the base that will begin to die at flowering time. You can cover these up with lower-growing flowers, or remove them to no ill effect.
Species & Styles
Popular allium species include Gladiator and Giganteum: these are formidable flowers in terms of size alone, with their flower heads growing 10-25cm across! Similarly, the well-named Mount Everest is one of the taller allium species at an average of 90cm tall.
Thinking about mixing and contrasting colours? The more popular varieties are iris purple, but there are plenty of others: the aforementioned ‘Mount Everest’ breed, as well as the smaller Graceful’ Beauty breed, both have a pale silver-lilac colouration. The later-blooming Allium atropurpureum and Allium sphaerocephalon have smaller, denser flower heads that bloom in a richer magenta (and the latter is accented with green).
Bright orange and yellow plants lend themselves to an eye-catching, summery effect. For a softer look, try a pale white or pink plant, or a plant with silver foliage.