Dahlia Seed Grow Guide
Welcome to our dahlia seed growing guide!
Whether you’ve purchased seeds from Reverie Flowers or you’re simply here to learn, we’re so glad you’ve found us. This guide will walk you through the simple paper towel method we use to germinate our own dahlia seeds here on the farm.
Every season we germinate around 1,000 dahlia seeds, and this season we’re increasing that to around 1,500 seedlings. The method you’ll find in this guide is the same one we use here on the farm.
Every dahlia seed is unique, so no two seedlings will ever be exactly the same. That’s one of the most exciting parts of growing dahlias from seed. We hope you enjoy the process and can’t wait to see what beautiful blooms you grow!
What You’ll Need
- Dahlia seeds
- Paper towel
- Water
- Spray bottle
- Zip lock bag or sealed container
- Permanent texta
- Seed raising mix
- Mini greenhouse with seed tray
- Small pots or trays (if potting up)
At the end of this guide, you’ll find a list of my favourite supplies and the products I personally use.
(IMAGE: Supplies laid out)
Quick Growing Guide
Sow: Late winter to early spring
Sow depth: 5 mm
Germination: 1 to 21+ days
Plant out: 6 to 8 weeks after sowing, once the risk of frost has passed
Flowers: Approximately 12 weeks from sowing
Position: Full sun
Spacing: 30 to 50 cm
Soil: Well drained, fertile soil
1. Germinating Your Seeds (Paper Towel Method)
Start by taking two sheets of paper towel and layering them on top of each other to make approximately two to three layers. I always start with three layers, as it makes the paper towel a little sturdier.
Lightly dampen the paper towel. You can rinse the layered paper towel under the tap, then thoroughly squeeze out all of the excess water. You want to ensure it is only damp, not wet, as a wet paper towel can cause your seeds to rot.
Place the seeds on one half of the paper towel, with the pointed end facing down. Placing them all the same way helps the root emerge in a consistent direction, making the seeds easier to monitor and handle when it’s time to plant.
Fold the other half of the paper towel over the seeds.
Place the folded paper towel inside a zip lock bag or sealed container. Make sure you label your bag by either writing on the front with a permanent marker or placing a plastic plant label inside with the seeds.
Keep the bag somewhere warm (around 20 to 24°C). I place mine in a warm spot, such as on the wall behind our wood fire in the dining room.
Check the paper towel every day to make sure it stays damp. If, after a few days or weeks, you notice it starting to dry out, lightly spritz it with a spray bottle to re-moisten it. You may start to see seeds sprouting in as little as 24 hours, while others can take several weeks to germinate. Don’t give up if nothing has happened after a few days or even a couple of weeks. Checking morning and night will also ensure the roots don’t become too large to handle before planting.
🌸 Elissa’s Tip
I check my seeds morning and night. Some can sprout incredibly quickly, and planting them as soon as the root appears makes them much easier to handle.
(IMAGE: layered paper towel ready to be wet under tap)
(IMAGE: Seeds being placed one direction onto paper towel)
2. Checking Your Seeds
Seeds can germinate in as little as 24 hours, while others may take a few weeks.
I plant my seeds as soon as I see the root beginning to emerge. Planting them early makes them easier to handle and helps prevent the roots from becoming too long or delicate.
🌸 Elissa’s Tip
If one seed has germinated, don’t assume they’re all ready. Keep checking the remaining seeds each day, as they can all sprout at different times.
3. Planting Germinated Seeds
Fill your pots or trays with seed raising mix.
Using the end of a pen (or something similar!), make holes approximately 5 mm deep in the seed raising mix.
Carefully pick up each seed and place it into the hole with the root pointing down.
Lightly cover with seed raising mix.
I plant my sprouted seeds into a mini greenhouse seed raising tray with a clear lid.
I bottom water the tray by filling the base with water, allowing the seed raising mix to absorb the moisture from below. Once all of the seeds are planted, I place the clear lid straight back on to help maintain warmth and humidity while the seedlings establish.
Continue to keep the seed raising mix moist, but not waterlogged. I continue to bottom water the tray as needed.
🌸 Elissa’s Tip
Before I start planting, I make all of my planting holes first using the end of a pen. It makes planting much quicker and means I spend less time handling the delicate roots.
(IMAGE: Seeds about a week of from sprouting)
4. Growing Your Seedlings
Once your seedlings emerge, move them into plenty of light to help them grow into strong, healthy plants.
Keep your seedlings:
- Evenly moist, but not waterlogged.
- Protected from frost.
- In a position with good airflow.
I keep the clear lid on my mini greenhouse for the first few weeks of growth. I grow all of my seedlings outside in a position that receives morning sun and afternoon shade.
If you’re growing your seedlings indoors, such as in a greenhouse or under lights, you’ll need to gradually harden them off before planting them outside. Start by placing them outside in a sheltered spot for a couple of hours each day, slowly increasing the time outdoors over about a week.
🌸 Elissa’s Tip
I find growing my seedlings outdoors from the beginning produces sturdy, hardy plants. Every garden is different though, so find a position that works best for your conditions.
(IMAGE: a favourite 2026 seedling)
5. Potting Up Your Seedlings
Once your seedlings have developed a few sets of true leaves and have outgrown their initial trays, some growers choose to pot them up into larger pots before planting them out into the garden.
Potting up gives seedlings more room for their roots to develop and can help produce larger, stronger plants before they are planted into their final growing position. It can also be useful if you need to delay planting out due to weather conditions or if you are growing seedlings in smaller trays.
We don’t personally pot our dahlia seedlings up and don’t find it necessary for our growing conditions. We plant our seedlings directly into the garden once they are around 6 to 8 weeks old, as we find this works well for us and allows us to keep the process simple. However, potting up can be a great option for other growers depending on their setup, climate and timing.
🌸 Elissa’s Tip
There is no one right way to grow dahlia seedlings. If potting up fits better with your space or growing conditions, it can be a helpful step to encourage strong root growth before planting out.
6. Planting Out
We usually plant our seedlings directly into the garden when they are around 6 to 8 weeks old.
It’s important to remember that young dahlia seedlings are not frost hardy. You need to wait until the risk of frost has completely passed for your area before planting them out into the garden. Planting too early can damage or even kill young seedlings, so it’s worth being patient and waiting for the right conditions.
For us here in Mid North SA, this is usually around mid to late October, but the timing will vary depending on your local climate and growing conditions.
If you’ve been growing your seedlings outdoors as I do, they’re already accustomed to the conditions and can be planted out once the risk of frost has passed.
If you’ve been growing your seedlings indoors, make sure they’ve been hardened off before planting them into the garden.
7. Growing to Flower
One of the most exciting parts of growing dahlias from seed is seeing each seedling bloom for the very first time.
Most of our seedlings begin flowering in around 12 weeks, although this can vary depending on the weather, growing conditions and the time of year they were started.
Unlike our mature dahlias, we don’t pinch our first year seedlings. We prefer to let them grow naturally so we can assess each plant’s natural growth habit and flower form. If you’d like to encourage a bushier plant and potentially more flowers, you can pinch the growing tip once the plant is well established.
To make the most of our growing space, we plant our seedlings much closer together than we do our tubers. This allows us to trial a large number of seedlings each season.
As the plants begin flowering, we assess every seedling carefully. If a seedling isn’t one we want to keep, we remove it straight away so we can focus our space and attention on the best performers.
(IMAGE: Two first year seedlings 2026)
8. What to Expect
Remember:
- Every seedling is genetically unique.
- Flowers may differ in colour, form, size and plant habit.
- Some seedlings may produce single flowers, while others may become beautiful doubles.
- Every seedling is a surprise, and you never know what beautiful bloom might appear!
That’s part of the excitement of growing dahlias from seed.
Enjoy the journey, and don’t forget to share your seedlings and blooms with us. We’d love to see what you’ve grown!
(IMAGE: 2026 seedlings)
9. My Favourite Supplies
These are a few of the products I personally use when growing my dahlia seedlings. There are plenty of great alternatives available, but these are the ones I’ve had success with.
Mini Greenhouse Seed Tray
The mini greenhouse seed tray I use for all of my seedlings:
https://www.bunnings.com.au/saxon-mini-green-house-with-seed-tray_p2960182
Seed Raising Mix
https://www.bunnings.com.au/seasol-10l-seed-raising-and-cutting-potting-mix_p0274166
Zip Lock Bags
https://www.woolworths.com.au/shop/productdetails/485590/hercules-twin-zip-storage-bag-jumbo
A Quick Note on Breeding Dahlias
If you're lucky enough to grow your own "unicorn", don't rush to release it! Most breeders grow and assess a new seedling for around four years before introducing it to the public. During this time, it's grown each season to make sure it performs consistently.
Some important traits breeders look for include:
- Strong, upright stems
- Flowers that face upwards or outwards
- No "bobble head" blooms
- Good tuber production that store well
- Stable colour and flower form each season
- Healthy, vigorous growth with plenty of blooms
Many beautiful seedlings are never released because they don't consistently meet these standards.
(IMAGE: Our first year seedling that won Best Seedling at the 2026 DSSA Show)
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If you’ve found this guide helpful, we’d love to see your seedlings and blooms. Tag @ReverieFlowers_ on Instagram or share a photo with us on Facebook so we can follow your dahlia journey.
If you have any questions, please reach out.
Happy growing!
Elissa
(IMAGE: Third year seedling to be released 2027)
