Now is a great time to start thinking about buying Allium bulbs to plant in September/October ready for a long season of colour and structure next year. With just a little bit of planning, you can have Alliums blooming from the spring right through to the autumn, and they are fantastic in a vase. Be sure to leave some in the garden - you can enjoy their architectural seedheads of standing tall throughout the autumn and winter.
Growing Alliums is easy as long as you plant them in the conditions they like - a free draining soil and plenty of sunshine. They don't like to sit in cold, damp soil - If you have heavy soil, improve drainage by adding plenty of grit when you plant the bulbs. The RHS website has a good growing guide.
Alliums are a firm favourite with garden designers - the RHS Chelsea Flower Show is always packed with Alliums and for good reason. Their dramatic form really attracts attention, and there's nothing quite like them for punctuating the border.
Associating well with lighter, diaphanous ornamental grasses, architectural Allium stands firm whilst Stipa tenuissima billows with the breeze. The highly effective contrast of texture and form magnifies the best features of each plant.
There's more than 500 species to choose from - here's 5 of my favourites to keep your garden in bloom from spring until autumn:
Allium hollandicum 'Purple Sensation'
Another of the earliest to flower, Purple Sensation really starts the season with a bang, with hundreds of star shaped flowers of a dramatic purple-violet. Growing to around 80 to 90cm tall, plant them 15cm apart to give the flowers a little room to show off their fantastic pom-pom heads from mid-spring.
A dainty, soft pink Allium, in flower from May. At 65cm tall, Roseum is great for the front of the border, slipped into the gaps 10cm apart, it will gently increase to form a colony over time.
One of the highlights of June, Allium christophii has huge heads packed with glistening metallic stars - irresistible to photographers and bees. The dried heads stand right through the winter and are well loved by crafty gardeners - Sarah Raven sprays them silver to use as festive decorations. I like to cut some of mine loose at the beginning of spring and let one or two slowly tumble round the garden through the rest of the year - in the hope they seed in surprising places.
Frequently used by Dutch garden designer Piet Oudolf, Allium sphaerocephalon (also known as Drumstick Allium) flowers from the end of June through August. Starting as a tiny teardrop bud, they develop into oval flowers atop a vertical stem, opening green and slowly becoming crimson-purple from the top down. One of the least expensive Alliums, try to plant them in large groups for the best effect - make sure they are in a sunny spot.
Flowering September and October, Allium tuberosum not only extends the flowering season, but the leaves are edible too. Also known as garlic chives, it is as happy in the border as it is in the vegetable garden. This Allium has a delicate white flower, and leaves that last all season.