Best alliums to grow

It often comes as a surprise to many gardeners that alliums are all members of the onion family and that they are some of the best flowers to grow for taking the show on from spring to summer. But once you handle the bulbs, the foliage and stems you’ll be left in no doubt about their heritage! Wild relatives such as three-cornered leek and wild garlic are also showy in late spring. But welcome these into your garden at your peril for pretty as they are, they can quickly spread to outgrow their welcome.

Other ornamental alliums are much less gregarious, although I have known the popular Allium ‘Purple Sensation’ (right) and the yellow A. moly produce so many offsets that they needed drastic thinning. Most are reserved in their habits and easily weeded out if they do get too enthusiastic.

What are the largest flowered alliums

The most commonly planted alliums bear purple blooms, but there are pink, white, yellow, cream, green and almost black-flowered species and hybrids. And the flowerheads come in a wide range of sizes too, though all following the basic rounded, multi-flowered design. The largest flowerheads in circumference are those of A. schubertii, with their widely dispersed, star-like blooms. The flower stalks of these aren’t the tallest, but their ‘see-through’ heads are the perfect addition to a sunny border where the purple flowers will blend and tone with all types of developing foliage on summer perennials.

Meanwhile the tallest and chunkiest varieties are often referred to as drumstick alliums – and include ‘Globemaster’ and ‘Gladiator’ (both with densely packed flower in mauve-purple) and the aptly-named, white-flowered ‘Mount Everest’. These are all great for a mid position in a border, so they can be seen and enjoyed before taller perennials grow up and around them.

Less commonly grown alliums

But I have a couple of real favourites. The first Allium nigrum (shown in the main image), is a species that seems less aptly named. It’s species name translates as black, though it bears white flowers. And the other oddity about it is that it smells neither of garlic or onions. I plant the bulbs in amongst roses where the charming flowerheads seem to bob and float ethereally before the roses take over the show. This allium is still less commonly grown than the eye-catching purple varieties, but it seems now to becoming better known.

Meanwhile, another that I’ve really enjoyed in recent years is A. ‘Silver Spring’ (right). Each individual flower has a well defined dark ‘eye’ with pink-stalked stamens at the centre of glowing white petals. I know I’m waxing lyrically about it, but it is a real gem.

Where to buy alliums

Mail order is readily offered on alliums for autumn delivery, but it’s well worth browsing the websites now for the ones you like and want to grow, as stocks often sell out quickly. Farmer Gracy, Van Meuwen and Avon Bulbs all offer excellent ranges with whole pages devoted to alliums on their websites.