Diverse dahlias

From the demure to the dazzling – dahlias are a varied bunch

In the world of late summer flowers, there are few that can compete with the dahlia. They're really quite something, not just the huge colour range but also the flower shape.

Waterlily type- D.'Taratahi Ruby'There are 14 different flower form classes in all, from tiny ball-shaped pompoms to spikey cactus-style flowers while others mimic anemones or waterlilies. Some have foliage so dark it’s almost black. With a little dedication, it’s possible to grow flowerheads the size of a football.

Our Trials Field is a sweetie tin of dahlias with 70 or so cultivars in the ground and 18 more in containers. All so pretty, all so different. On average there are 100-150 new cultivars registered every year, with plant breeders trying to find the elusive characteristics of frost hardiness, perfume or blue colouring.

Dahlias have dipped in aSingle-flowered D. 'Honka'nd out of fashion over the years. Some think they’re gaudy, while others relish their flamboyance. Interestingly, in the Japanese language of flowers, the dahlia means ‘good taste’, which we, in the dahlia fan club, rather like.

Aside from the choices of colour and size that means they fit in with any scheme, they look incredible in mixed borders in late summer and autumn. Check them out in the Mixed Borders at RHS Garden Wisley. We've grown a range our Cutting Garden this year too as they also make stunning cut flowers. It’s really simple to remove side buds so you get one strong flowerhead on a long, straight stem, perfect for a vase.

Dahlias have a repuSemi-cactus D. Nuit d'Etetation for being tricky to grow, but that’s undeserved. Traditionally, they’re dug up and the tubers stored in frost-free conditions over winter. It will vary of course on your own local conditions, but with a generous mulch, they can survive in situ over winter. What you need to watch out for is the emerging growth that can be swiftly chomped by slugs in early May. Later, earwigs nibble the flowers, but not usually so badly.

Dahlias really are blooming lovely! If you’re as enchanted as we are, why not come along to the Dahlia study day on Wednesday 23 September. Entry is free once in the garden with no booking required. If you want to come and just marvel, visit the National Dahlia Society Show at the Wisley Flower Show, 8-13 September.

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