FLORAL FIREWORKS!
Alliums will light up the late spring garden with a majestic display of glorious exploding flowerheads
ALLIUMS are a major part of our late spring display. They are spectacular plants, from the smallest chive flower to the crazy explosion of Allium schubertii, of which more later.
The first to appear is A. hollandicum (also known as A. aflatunense). It is about 90cm (3ft) tall, with lilac flowers fringed with a silvery halo. There is a white form, too. As the flowers emerge, the colour shows through the thin tissue of sheath and they look like flat-topped thistles, but then open out to a cylinder.
The leaves, which fold halfway along and droop in an idiosyncratic manner, have a tendency to start to die back at the tips before the plant comes into flower. This is not due to any illness or problem — it’s simply a common feature of early alliums that the foliage dies back before the flowers fully open. A. hollandicum ‘Purple Sensation’ — which is both purple and sensational — has lollipop globes made up of scores of individual florets, and they create an open carapace of flowers that not only look dramatic and stylish, but are also excellent for wildlife.
The first ones appear here towards the end of April, and by mid-May they are in their pomp. ‘Purple Sensation’ has a richness of colour that makes an ideal foil for the intense greens and yellows of May and June.
As plants, they require nothing of the gardener other than planting, and the best time to do that is autumn — although I have successfully planted the bulbs as late as February.
A. cristophii follows in midMay, with its huge, exploding balls of flower. They work well with softer companion colours than those used with ‘Purple Sensation’, which is why we grow them alongside old roses, sweet peas, geraniums and other pale and pastel colours.
As the flowers fade, the dramatic flowerheads become drier and hold their shape for months on end, albeit without colour. We often collect them in this mummified state to put in a vase, where they last for ages.
Like ‘Purple Sensation’, A. cristophii seeds like mad and needs thinning otherwise it can crowd a border.
And so back to A. schubertii. This ornamental onion takes the exploding flowerhead to another level of artistic extreme. From a very short stem, the flower flies apart into a ball the size of a melon that is made up of dozens of florets, each on a stalk of a different length.
It can get lost at the back of a border, so put it near the front. It dries easily and will stay in shape to be wondered at for months.
Meanwhile, A. giganteum is a colossal drumstick of a flower, reaching 2m (6ft) tall in our rich clay loam. It is almost like those box or holly bushes that are clipped into topiary pompoms, and one year we had them marching all the way down the Long Walk. However, the huge bulbs are expensive and need the best drainage possible, as I learnt to my cost. They will rot very quickly in a wet winter, and we lost the lot. As a rule, this applies to all alliums, which prefer a sunny, well-drained site.
Rather later — and last of the alliums here — is A. sphaerocephalon. It is much smaller than all of the previous ones, and its natural habitat is a meadow. In late July and August, it makes a wonderful tapestry of conical flowerheads of mauve and ruby pink. Its only weakness is that on our heavy soil it tends to flop, but bounded by a box hedge, it will tumble onto that rather than fall right over.