Alliums – My Favourite Varieties and How to Grow Them

There are a great many varieties of Alliums to choose from, depending on their height, colour, and flowering time. I tend to plant varieties that produce larger flowers and stronger stems. Here are some of the Allium varieties I regularly use on my landscaping projects.

The taller, more robust, large-flowering ‘Ambassador’ has a deep purple flower around 6–8 inches across. ‘White Giant’ is slightly smaller, and as the name suggests, produces beautiful white blooms. ‘Giganteum’ grows a little taller than ‘Ambassador’ with a similar flower, while ‘Christophii’ has shorter stems but wonderfully open flower heads that can reach 12 inches across.

My personal favourite has to be ‘Globemaster’. It produces tall, sturdy stems that withstand windy, wet conditions without support. The large blue-purple flowers measure around 6–8 inches across, with tightly packed, star-shaped florets — a glorious plant to have in the garden.

Allium 'Globemaster'

I like to dot-plant Alliums among shrubs and perennials, whether in new projects or existing borders. They look striking when planted in groups and flower for 6–8 weeks from late spring into early summer. That’s not the end, though — as the blooms turn to seed, they fade into a lovely caramel colour, looking beautifully architectural for another five to six weeks.

Allium 'Globemaster'

‘Globemaster’ and the other varieties mentioned are excellent for bumblebees, especially as they provide early, sizeable flowers. (And don’t forget to put a few bee hotels in your garden!) Alliums like light, sandy soils and dislike sitting in wet clay, particularly over winter. If you have heavy ground, you’ll need to improve the soil and drainage. Alternatively, they grow brilliantly in pots — around three to five bulbs per container.

Alliums prefer full sun and warm positions. The best time to buy bulbs is between early October and late November, and they should be planted as soon as possible. All is not lost if you miss this window — most garden centres stock grown-on plants in spring, though they will be more expensive. I always look for the largest bulbs, about the size of a small apple, to ensure a good-sized flower in the first year.

I normally plant the bulbs around 7–8 inches deep. In the first year, you can expect flowers around 24–30 inches tall with a 6-inch head. After a couple of years, a happy plant can reach 40–48 inches, and I’ve even managed 60 inches. The main bulb produces offsets, each creating a new flower. Once a few appear, you can lift and divide them carefully in late autumn — well worth doing, as each bulb costs between £6 and £8, and it’s satisfying to see the new ones develop.

Allium ‘Globemaster’ is a striking, long-lived flower — perfect mixed into existing planting or new schemes. Easy to grow in the right soil and position, great for bees, and quick to reproduce, it gives a wonderful show year after year.