Growing dahlias from seed is exciting. A plant grown from seed will not grow true to the parent plant.  It will share some characteristics, but you will never know which other dahlias grown nearby have contributed the pollen to create your seeds.  Open pollinated means the bees have done the work of spreading the pollen around.

Here is a step-by-step guide to help you get started:

1. When to Start

  • Start seeds indoors about 6–8 weeks before your last expected frost.

2. What You’ll Need

  • Dahlia seeds

  • Seed trays or small pots

  • Seed starting compost (light and free-draining)

  • Heat mat or warm windowsill (optional)

  • Grow light or sunny window

  • Spray bottle or gentle watering can

3. Starting Seeds Indoors

  1. Fill trays/pots with moist seed compost.

  2. Sow seeds about 0.5 cm deep. Cover lightly with soil.

  3. Water gently to moisten the soil (don’t soak).

  4. Keep them warm—21–24°C is ideal for germination.

  5. Once sprouted (usually within 5–10 days), move them to a bright windowsill or under grow lights for 12–16 hours per day.

4. Transplanting Seedlings

  • Once seedlings have 2–3 sets of true leaves, transplant them into slightly larger pots.

  • Before planting outdoors, harden them off by gradually exposing them to outdoor conditions over 7–10 days.

5. Planting Outdoors

  • Wait until all danger of frost has passed and the soil is warm.

  • Choose a sunny location with well-draining soil.

  • Space plants 30–45 cm apart.

  • Plant them a little deeper than they were in the pots.

6. Care & Maintenance

  • Water regularly, but allow the soil to dry a bit between waterings.

  • Pinch out the main growing tip when the plant is around 20–25 cm tall to encourage bushier growth.

  • Use a balanced or low-nitrogen fertiliser every month.

  • Stake taller varieties early to avoid damage from wind or top-heavy blooms.

7. Bonus: Saving Tubers or Seeds

  • Tubers: Seed-grown dahlias usually form tubers by the end of the growing season. Lift and store them over winter in a cool, dry place.

  • Seeds: Allow some flower heads to go to seed, dry them on the plant, then collect and store in a cool, dry spot for next season.

Bouquets of pink and red flowers wrapped in brown paper with farm labels.