Ornamental onions are a delight in the garden in high summer
You know summer is on the horizon when dramatic displays of ornamental onions or alliums approach their peak, stretching their glorious globes and bold bobbles above leafy perennials still preparing for glory. But after the main early June show why not develop the cavalcade of blossom by using other allium species and varieties that will propel your displays into high summer. While the time for planting dry bulbs is in autumn do look out for potted plants in nurseries, garden centres and horticultural shows that you can slip into plantings to try them out. Alliums are so useful, as their long-lasting flower heads are supported on strong stems that enable them to poke above or mingle with other perennials, which can be used to mask or disguise their foliage which has no visual quality or which withers before they flower. For serious impact they need to be planted in groups of at least five or seven, or more with smaller, slighter forms. Although the look good in close proximity with perennials they still need plenty of light and air so they continue to grow healthily for years to come and are not crowded out by neighbours. They can also be grown in pots and also make good cut flowers and are highly attractive to bees and other pollinators. Plant dry bulbs in October around 3-4in deep in a sunny position in moist, but well-drained soil. Although attractive in seed many alliums will seed around, so remove flower heads when spent if you don’t want this to happen.