Grow Dahlias from Seed

How to grow dahlias from seed

Follow the advice in this quick guide to sow and grow dahlias from seed.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
At its best
At its best

Plant is not at its best in January

Plant is not at its best in February

Plant is not at its best in March

Plant is not at its best in April

Plant is not at its best in May

Plant is not at its best in June

Plant is not at its best in July

Plant is not at its best in August

Plant is at its best in September

Plant is at its best in October

Plant is at its best in November

Plant is not at its best in December

To do
To do

Do not To do in January

Do To do in February

Do To do in March

Do To do in April

Do not To do in May

Do not To do in June

Do not To do in July

Do not To do in August

Do not To do in September

Do not To do in October

Do not To do in November

Do not To do in December

Sown in late winter or early spring in a greenhouse or propagator, dahlia seeds will produce young plants ready to plant outdoors in late May to flower this year.

Seed companies sell a range of quick-growing bedding dahlias that are suitable for growing from seed. You can also use this method for sowing seeds saved from your own dahlia plants at the end of the previous season.

Related content:

Follow these easy steps on how to sow dahlia seeds.

Seed companies sell a range of quick-growing bedding dahlias that are suitable for growing from seed.

You will need

  • 10cm pot or seed tray
  • Multi-purpose compost
  • Dahlia seeds
  • Plant label and pencil
  • Clear polythene bag and rubber band (for pot) or propagator lid (for seed tray)
Advertisement

Total time:

Step 1

Fill a pot or seed tray with moist seed compost and lightly firm the surface. Gently push your dahlia seeds into the compost. Don’t forget to label your seeds. Cover pots with an inflated clear polythene bag, held in place with a rubber band. If sown in seed trays, cover with a propagator lid. 

sowing-dahlia-seed-2

Step 2

Seedlings will germinate within a couple of weeks. Once the ‘true’ leaves have grown, seedlings are ready to transplant into individual pots. Hold plants by their leaves and gently tease them out of the soil. 

transplanting-dahlia-seedlings-2

Step 3

Gently transplant seedlings in 10cm pots of multipurpose compost, firm and and water well. In mid-May, harden off plants by standing them outdoors during the day and bringing them in at night. Plant them in their final positions once all risk of frost has passed.

young-dahlia-plant-2
Advertisement

Allow a few dahlia flowers to set seed for collection at the end of September. Save them in an envelope over winter to sow in February. You’ll get a wonderful mixture of different flower shapes and colours from the resulting plants.