Alliums are the magic wands of garden designers, and this versatile family of bulbs should work its magic in all our gardens. The star-studded pompoms on rod-straight stems look wonderful rising head and shoulders above clipped box balls, echoing their shape, popping up randomly among the lavender or contrasting their perfect, globed heads with spears of flowering iris.
Early enough to spice up the aquilegias, they fill the lean gap between spring and summer, taking the baton from the tulips and hitting their stride before the roses get going. Bees and butterflies adore them. Best news of all, the bulbs are easy to grow, both in border and container, they naturalise over time, and the time to plant them is right now.
Alliums blend into any and every kind of plot, from modern minimalist to densely planted cottage garden, and there are myriad ways to use them, from demure, pink-flowered chives that make the prettiest edging to sensational Allium cristophii, with sparkly, silvery heads up to nine inches in diameter, that rival any garden sculpture.
At Great Dixter, the drumstick blooms of signature allium Purple Sensation, several shades richer than their close relative A hollandicum, drift through ladybird poppies, making a striking contrast to the scarlet, black-blotched flowers. Use both these hollandicum alliums together, darker and lighter, to fabulous light-and-shade effect.
At innovative Sussex Prairies, Paul and Pauline McBride couldn’t afford a water rill to run down the long space, so instead planted what they call a pink river of Allium Summer Beauty, a lilac-tinged pink evergreen allium that has a clump-forming habit, so throws out several stems from each bulb. And when the alliums are past their best, ornamental grass Miscanthus Silverspinner takes over, veiling Summer Beauty’s dainty seedheads.
If you’re looking for impact, Allium Globemaster, with its giant mauve, tightly packed flowerheads on fat 3ft stems, is the one to choose. Just a trio will pack a big punch in a small border. Dynamic plantsmen Nigel Dunnett and James Hitchmough scattered spectacular Globemaster through the Pictorial Meadow at the Queen Elizabeth Olympic Park, using them to create strong visual anchors for the wildflowers.
PERFECT STARRY SPHERES
In a far smaller space, London designer Charlotte Rowe uses white Nigrum alliums to add drama to a contemporary courtyard, and plants groups of white, 4ft-tall, large-headed Mount Everest among lime green euphorbia, beneath pleached hornbeams, to add vertical interest to a cool green colour scheme.
Garden designer and BBC Gardener’s World presenter Nick Bailey favours the other end of the allium colour spectrum, and is a fool for the lesser-known deep, dark Allium atropurpureum. “It has really deep, inky purple flowerheads that look amazing with any silver, blue and pale-coloured plants. It’s also rugged of stem, so I do a bit of a cheat when the flowers have faded and the stems have begun to rock at the base. I tug them out, cut them off, and push them back into the ground, which gives them another six weeks to display their seedheads.”
Allium cristophii is another Bailey favourite. “Each flowerhead is a perfect sphere of interlinking stars. There is no other plant with quite that metallic sheen. The understorey of any sun-loving herbaceous plant is ideal for cristophii to grow through, but my most successful planting is with Nepeta Walker’s Low. When the seedheads have formed, I cut the stems and nestle the heads into the catmint.”
For London garden designer Claire Mee, alliums are the spring and early summer version of agapanthus. “They’re a great transition plant. You can use them anywhere in the garden, but a favourite combination of mine is to weave the only true blue ornamental onion, Allium caeruleum, through a drift of ornamental grasses or green-and-white Astrantia Shaggy.
“I’ve just planted them beneath crab apple Malus Red Sentinel, so as the blossom finishes above, the alliums beneath take over. For later on in summer, I like to use the small, lozenge-headed, blackcurrant Allium sphaerocephalon. The only rule I have in planting schemes with alliums is to position them in the middle of a bed or border rather than the front, so the surrounding plants camouflage the foliage, which tends to die down when the flowers start to bloom.”