Dahlias

From July until the first frost — the summer garden that outdoes itself

Dahlias: the queens of the summer garden

Which dahlia suits your garden?

Pinching out for more flowers

Frequently asked questions about dahlias

• When should you plant dahlia tubers?
  There are two ways to start dahlia tubers. You can start them off indoors from March or April: place the tubers in a pot filled with potting compost in a light, frost-free spot. After the Ice Saints (mid-May), move them outdoors. You can also plant them directly outdoors, but only after mid-May, once the risk of night frost has passed. Dahlias are not hardy and can freeze in frost.
• How deep should you plant dahlia tubers?
  Plant dahlia tubers 10 to 15 centimetres deep, with the old stem pointing upwards. Space tall varieties 40 to 60 centimetres apart, and compact bedding dahlias 20 to 30 centimetres apart. Dahlias thrive in a sunny, sheltered spot with nutrient-rich, well-drained soil. The tubers can rot in wet, heavy soil — improve the soil with compost before planting.
• Do you need to dig up dahlia tubers in winter?
  Yes, in most cases you should. Dahlias are not hardy and can freeze if the tubers are left in the ground. Dig them up after the first frost, allow them to dry thoroughly, and store them frost-free in a dark, dry place — a box lined with newspaper in the cellar works well. Check the tubers regularly for rot or dehydration. In mild winters and in well-drained soil, you can try overwintering them under a thick layer of mulch, but this carries a risk.
• Can you plant dahlias in a pot?
  Certainly. Choose a spacious pot with drainage — at least 30 centimetres deep for compact varieties, larger for tall ones. Use nutrient-rich potting compost and water regularly, as pots dry out faster than open ground. Compact bedding dahlias are ideal for pots and balconies. Tall varieties also need a sturdy stake when grown in a pot.
• Are dahlias bee-friendly?
  Not all dahlias are equally bee-friendly. Double-flowered varieties, such as dinnerplate dahlias, are difficult for bees to access because the nectar is hidden. Open-centre dahlias, fringed dahlias and single-flowered varieties, however, are easily accessible to bees and butterflies. At Natural Bulbs, you’ll find a selection of bee-friendly dahlias, including the Dahlia Bee Mix Pink-Red and the Dahlia Bee Mix Collarette — specially curated for maximum bee-friendly impact.
• When do dahlias flower?
  Dahlias flower from July until the first frost in October or November — depending on the year and the region. If you want them to flower earlier, you can force the tubers: by starting them indoors as early as March or April, the plant may sometimes flower as early as June. Flowering lasts for months on end, provided you remove spent flowers regularly.