The Dahlia: a charming coquette

Hot or not

In 1789, a number of dahlias were sent from Mexico to the botanical garden in Madrid along with the recommendation to use them as food. At the time, this recommendation resulted in little popularity. All that changed when Joséphine de Beauharnais, Napoleon’s wife, had a sudden whim to fill her entire garden with dahlias. Having set the trend, everyone wanted these charming coquettes in their garden. Dahlias then became so popular, however, that they soon became affordable; their status changed from ‘exclusive’ to ‘ordinary’. For years, the charming Dahlia had to make do with this undeserved status. Fortunately, however, she has been rediscovered! This lady is again a hot item in the garden.

Dahlia groups

Since the enchanting Dahlia was rediscovered, more and more varieties have become available. They range from small ones whose beauty rests on their simplicity to huge ones with dazzling colours. To help you find your way through the forest of dahlias, they have been classified into twelve groups. Be prepared, however, because once you’ve fallen for the Dahlia, you’ll never want to be without her.

Varieties in this group, such as Dahlia ‘Polka’, have one or more rows of petals around a centre made up of a cluster of smaller petals. Anemone-flowered dahlias grow to a height of 60 to 90 cm.

Varieties in this group, such as Dahlia ‘Jowey Winnie’, look exactly as their name suggests. Their flowers are shaped like a ball. Each inflorescence is packed with blunt or rounded petals, with each petal curled up into a roll. Ball dahlias can easily become 150 cm. tall!

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Cactus dahlias, like Dahlia ‘Popular Guest’, are double-flowered and filled with tapered petals ending in a point that looks as sharp as a real cactus spine. Cactus dahlias can grow to a height of 150 cm.

Dahlias in this group, such as Dahlia ‘Hy Pimento’, are double-flowered with pointed petals. Unlike cactus dahlias, however, their petals are broader and shorter. Semi-cactus dahlias can reach a height of 150 cm.

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Decorative dahlias, like Dahlia ‘Pink Ribbon’, have flat inflorescences with broad blunt petals. Decorative dahlias can grow to a height of 150 cm.

Dinner Plate 
The flowers produced by the Dinner Plate dahlias such as Dahlia ‘Babylon Roze’, are truly gigantic! They can reach a diameter of 30 cm – larger than an adult’s face. The Dinner Plate dahlias originate from the Decorative dahlias; both are double-flowered. What makes the Dinner Plate dahlias different, however, are their long flat wide ray petals.

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Dahlias in this group, such as Dahlia ‘HS Party’, have a single row of petals surrounding a flat surface made up of very short upright petals. Single-flowered dahlias grow to 40 to 60 cm in height.

Collerettes, such as Dahlia ‘Pooh’, have flat flowers. Surrounding their flat centre is an outer ring of flat petals and an inner ring of upright petals. Collerette dahlias grow to between 75 and 120 cm tall.

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The members of this group, including Dahlia ‘Moonfire’, resemble single-flowered dahlias but the diameter of their flowers makes them much smaller: just 6 to 10 cm across. Mignon dahlias are special in that they grow very well in flower pots. Mignon dahlias grow to about 50 cm tall.

Peony-flowered dahlias such as Dahlia ‘Bishop of Canterbury’ are double-flowered with rounded petals. As you would expect, they resemble peonies. Peony-flowered dahlias can reach a height of 100 cm. 

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The flowers of dahlias in this group, such as Dahlia ‘Little Robert’, look very much like the pompons waved about by cheerleaders. The flowers are semi-spherical and are covered with blunt or rounded petals, each petal curled up into a roll. Pompon dahlias grow to between 80 and 120 cm tall.

Dahlias in this group, such as Dahlia ‘Nagano’, are flat and double-flowered. The slightly rounded tips of their petals make their flowers look like waterlilies. These plants, however, can be planted in your garden instead of in the water. Waterlily dahlias can grow to a height of 120 cm.

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Interesting facts

  • The Dahlia was named after Andreas Dahl, a Swedish botanist who was a student of the famous naturalist, Carl Linnaeus. 
  • Dahlias have a long flowering period. Their first flowers appear in July, and the plants remain covered in flowers until the first freeze. 
  • The tuber, leaves and flowers of dahlias are edible. Taste them sometime: it’s worth a try! The intense colours of their petals add a beautiful touch to the presentation of a special dish.
  • In the Dahlia’s native country of Mexico, these plants can reach a height of six metres when growing in their natural habitat.
  • There are more than 20,000 varieties of dahlias. Not all of them are as easily available as some, but this is still an impressive number.
  • Some dahlia flowers are even black due to a high concentration of a substance known as anthocyanin.
  • Whenever you pinch flowers from a dahlia plant, it produces even more buds. That makes cutting them twice as nice: you have flowers in a vase and more flowers in the garden.


  • Planning a party? Wear a dahlia flower behind your ear or in your hair. Everyone is sure to give you a nice smile.

What if you fall in love?

Have you fallen for the gorgeous looks of the Dahlia? If so, don’t wait any longer: start on your Dahlia adventure now. The best time to plant dahlias is in the month of May. Locate a place in the garden where the sun shines most of the day and dig a planting hole there. Or plant them in pots and place them in a sunny spot on the patio. Wherever you plant them, enrich the soil with some organic fertiliser and then plant the dahlia tubers. Make sure to plant them just beneath the soil surface so that they can quickly soak up the warmth of the sun. The first shoots will emerge within a few weeks. We wish you a long and happy relationship!