Hundreds of small, star shaped, flowers unfurl to form a tight floral sphere. The tall stems of Allium giganteum grow to around 120cm tall and it is this height that can be used to create memorable floral displays, adding a whole other dimension to the garden.
The 15cm balls of blooms open midsummer, (late November, early December). The flower is handsome from the get go and lasts for around seven or eight weeks. The attractive heads begin green then, as the buds open, the purple shines through. The show doesn’t stop there though, even as the bloom turns golden brown they shine in the garden. They also make excellent cut flowers and the dried seed heads are used as Christmas decorations in our home.
Alliums are tough, hardy, and beautiful too! As members of the onion family, their bruised, or crushed foliage smells just like onions.
Plant Alliums into well drained soil in a sunny position. The drainage is important as the bulbs rot easily if left in soggy soils. Adding some lime and compost to the soil will give them a good start in the garden.
They will need at least six hours of sun and a warm spot in the garden to thrive. As the stems of Allium giganteum are tall, you should shelter them from strong winds because while they are strong, there is only so much they can do and let’s face it, they are expensive so it is best to get the most out of them.
Why are they expensive? Because the bulbs are slow to multiply and it takes around five years to flower from seed. You can leave the seed to fall, or collect once ripened for planting in autumn.
Plant to a depth of around 10-15cm, or twice the diameter of the bulb. Once planted, the bulbs are best left to naturalise. This means you can relax and leave them in the ground year after year and just enjoy flowers each summer. To help them on the way, add a well balanced fertiliser when they are flowering. As they fade, don’t forget to mark their position (we use wooden kebab sticks just out of the ground) as you don’t want to put a spade through one!
Our Tip: Plant amongst summer perennials that emerge mid to late spring and will keep the fading foliage hidden. As with most Alliums, the leaves begin yellow as the blooms take off.
It is a good idea to protect the new foliage from slugs and snails (it emerges in spring). One last thing, they like to be relatively dry during summer dormancy or require sharp drainage.