Allium bulbs, also known as ornamental onions, offer stunning spherical blooms and tall elegant stems, adding wow-factor to your garden displays. Our eye-catching alliums collection includes giant purple 'Globemaster' spheres, 'Schubertii's' starburst blooms and the elegantly contrasting colours of 'Graceful Beauty'. To help your flower bulbs prosper, we've created a library of guides including 'how to grow alliums'.
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Allium bulbs bloom in summer with starbursts of purple, white and pink. Some of these summer bulbs have spectacularly large flowers and tall stems that rise clear of the herbaceous border to produce a haze of colour above your beds. Others sprout smaller blooms in deep colours with more blooms per bulb. Here we answer some frequently asked questions to help you choose the perfect allium for your garden.
Allium christophii blooms reach a diameter of 20cm on stems up to 60cm tall. Plant this impressive allium among low-growing perennials where the flower heads can burst into bloom from May until July. If you’re after a minimalist look, then choose allium stipitatum 'Mount Everest' to enjoy extra long whippy stems that reach up to 1.2m crested with elegant, snow white blooms. Read our allium bulb masterclass for more inspiration.
Allium sphaerocephalon blooms reach 4cm across and burst from the base of the plant in masses. Allium carolinianum 'Rosy Dream' is another multi-headed variety that produces a mauve fuzz of blooms. These varieties are notable for their thickly growing flower heads.
Plant a mix of allium varieties to enjoy the longest flowering season. Mix allium ‘Hair’ with allium schubertii for a more airy display that begins at the beginning of summer. The flower heads are large but less densely packed than other varieties. Leave allium flowers to run to seed to extend their season of interest. The seed heads are delightfully architectural as they dry in autumn and are a sight to behold when sparkling with frost.
One of the latest flowering alliums is 'Lavender Bubbles'. This lower growing, multi-headed variety reaches a height of 35cm and blooms in August and September. Plant this delightful variety in a gravel garden or cottage garden and this low-maintenance bulb will reward you with reliable flowers every year.
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