The Gravel Garden simply wouldn’t be the same without alliums. A fabulous bulb for anyone creating their own drought-resistant garden. They are dramatic, decorative and best of all, easy to grow. They can add so much to the look of a border with their spherical heads. Just make sure you can give them a free-draining, light soil with plenty of sunshine, and you will be guaranteed success.
Part of the onion family, alliums have showy, interesting heads that are made up of tens and tens of tiny, individual star-like flowers. They start to open in late spring, once the tulips have finished and provide bright, bold colour and structure all summer. The blooms vary hugely in size. Some are the size of a ping pong ball whilst others can be as large as a football.
We grow many alliums here, many planted in drifts throughout the Gravel Garden. Here are just a few of our most popular varieties:
- A. cristophii – Huge, globular heads made up of nearly one hundred metallic, lilac-purple stars on delicate spoke-like stems.
- A. atropurpureum – The darkest of all the ornamental onions. Dense blackish-purple flowers stand at nearly three feet high.
- A. hollandicum ‘Purple Sensation’ – Probably the best know allium. Standing three feet tall with rich, mauve flowers. The Chelsea Flower Show wouldn’t be the same without it.
- A. karataviense – Shorter growing with two broad, curved, fleshy leaves cradling a pinky-beige flower nearly the size of a tennis ball.
- A. sphaerocephalon – Thin stalks carry wine-red and plum shaped flowers usually a little later than the other types.
Alliums look particularly good in amongst Mediterranean plants, for example, lavender, phlomis, artemisia and sage. However, one of my personal favourite combinations are alliums planted through clumps of the airy ornamental grass Stipa tenuissima.
When planting bulbs, common advice is to group several together to provide impact. This is true for the smaller alliums, although you will find it is not necessary with the larger flowering forms. Planting in drifts will create a more natural feel and help add another layer of depth to the border.
Alliums offer more than just their colour too. By the end of the summer, the nectar-rich flowers start to fade and dry. The strong, stiff stems can then stand proudly well into autumn. Do however, prepare yourself for the potential of many seedlings appearing the following spring. I choose to cut them off at the base and bring them indoors to keep as dried flowers. I have had several in a large vase in my living room for almost three years now.
We regularly stock over 20 different alliums on our Nursery. We pot them in the autumn so they can root over winter and be ready for sale in early spring. Read about the advantages of planting bulbs from pots in spring, in a blog posted back in January.