How to Start Dahlia Tubers

Big and bold, dahlias provide large, intricate blooms in a variety of colours. Dahlias bloom from midsummer and into fall, depending on the variety. These tender perennials grow from a tuberous root that stores much of the plants needs for healthy flowering. Since they cannot tolerate freezing weather, the dahlia tubers must be dug up and stored before fall frost then replanted again in spring. Planting the tubers properly ensures they flower beautifully this year while also storing up the nutrients they need for next year.

Combine one part peat moss, one part perlite and one part sterilised soil or compost. Fill an 8-inch diameter pot to within 3 inches of the rim with the soil mixture.

Inspect the dahlia tuber for soft spots that indicate rot or mouldy areas. Cut these off any damaged areas with a clean knife.

Set the dahlia tuber on top the growing medium with the buds facing upward. Cover the tubers with 1 to 2 inches of growing mix.

Water the soil from the top until the excess drains out the bottom. Water when the soil surface begins to dry out, keeping the growing medium moist at all times.

Move the pot to a window that receives full sunlight once the dahlia sprouts emerge. Continue to water as needed to maintain soil moisture.


Start dahlia tubers six weeks before the last expected spring frost in your area. Plant the sprouted tubers in the garden after all frost danger is past.

Things You'll Need

  • Peat moss
  • Perlite
  • Compost
  • Pot
  • Tubers
  • Knife
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About the Author

Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.