How to Grow Dahlias from Seed (Step by Step Guide)
Help to Grow Dahlia plants from seed
Latin Name : Dahlia
Growing dahlias from seed is an easy and affordable way to enjoy a stunning display of colour in your garden.
If you want a specific variety of dahlia then you’ll need to buy and grow tubers. For unique vibrant colours and forms try growing from seed.
Best Place to Grow Dahlias
Dahlias are ideal for an herbaceous border and make good cut flowers. They are grown as a half hardy annual in the UK but as a half hardy perennial in other parts of the world. They like a sunny, well drained spot, which has been enriched with well-rotted compost.
Step by Step Guide to Growing Dahlia Seeds
Sow the seeds indoors in quality peat free seed compost, between February to April, approximately 6 weeks before your last expected frost date.
Sow in trays of moist compost covering the seeds about 0.5cm deep.
Dahlia Seeds Germination Conditions
After planting, spray the compost to make sure it is moist but not waterlogged.
Keep in a warm, humid location at temperature of 20oC; a windowsill propagator or heated mat is ideal.
How Long Do Dahlia Seeds Take to Germinate?
Germination may be sporadic; typically between 7 -14 days.
When they have germinated remove any cover to allow the air to flow and avoid damping off.
Reduce the temperature to about 15oC and grow them on until large enough to be potted on.
When to Pot Up Dahlia Seedlings
Allow the seedlings to develop 2 sets of true leaves so they are big enough to handle.
Transplant them into individual pots.
Continue to provide good light and grow them on in cooler but frost-free location until they are ready to plant out.
How to Harden Off Dahlia Plants
Dahlias are frost tender plants, so it is important to harden off your plants before planting them out in their final position.
Move the plants from the greenhouse or windowsill initially to a sheltered spot outside.
Keep an eye on the weather and if it turns cold then bring them back in at night, returning them outside in the daytime.
Allow a couple of weeks to fully harden off your plants.
When to Plant Out Dahlia Plants
When all risk of frost has passed, plant out in a sunny well drained spot which has benefited from some extra compost or manure. Space the plants out 15–30 cm apart (check the requirements of individual varieties). The dwarf varieties can be grown in large pots or containers.
How to Care for Dahlia Plants
Care Tips
Water regularly in dry weather.
Feed every two weeks with a balanced liquid fertiliser once flowering begins.
Deadhead spent blooms to encourage continuous flowering.
Watchout for slugs.
The plants will reward you with beautiful flowers through the summer into autumn. Many of the varieties available make gorgeous cut flowers.
Best Dahlia Varieties to Grow from Seed
Browse our full range and buy Dahlia Seeds Online
There are a lovely range of colours available from seed to get you started:
Dahlia Figaro White seeds- semi double white flower (also red version)
Dahlia Coltness mix seeds- large single blooms, mixed colours
Dahlia Pompone Double mix seeds- compact globular flowers, mixed colours
Dahlia Cactus Flowered mix seeds- quilled petals, mixed colours