9 things you probably don’t know about dahlias

When should you plant your dahlia tubers? Find out here... Brush up on your dahlia know-how with these fast facts.

Credit: Netherlands Flower Bulbs

Brush up on your dahlia know-how with these fast facts


  • There are more than 30 species and over 20,000 cultivars of dahlias.
  • The original French diva, Marie Antoinette, fell head over heels for dahlias when they were a new arrival in Europe, and now there’s a variety named after her.
  • Pompon-shaped varieties are the toughest types: they’re extremely resistant to cold and rainy weather.
  • There’s no such thing as a black dahlia. They come in just about every shade under the sun, except true blue and black. “Black” dahlias are actually burgundy.
  • More on dahlias!

    For more on these gorgeous late-summer bloomers, check out the our Delightful Guide to the Ever-Stunning Dahlia.

  • It’s easy to find professionally pre-grown dahlias in nursery pots at garden centres. Transfer them to a decorative pot or into your garden in the late summer.
  • The tallest-growing shapes are spiky cacti, decorative double flowers with flat-tipped petals, and globe-shaped 
  • Dahlias originated as a wildflower in the high mountain regions of Mexico and Guatemala. That’s why they naturally work well and bloom happily in cool fall breezes.
  • It’s ideal to plant tubers sometime around the May long weekend.
  • Tubers can’t be separated because their roots are so thick. Once a tuber is separated from its growing point, it won’t send out shoots.