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Starting Dahlias Indoors from Seed – Don’t Be Intimidated!

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Can you imagine growing a show-stopping dahlia from seed?! Starting dahlias indoors from seed is easier than you might expect, and it’s one of my absolute favorite things to experiment with in the garden. Such an impressive flower comes from such an unimposing seed.

The first time we grew dahlias was in 2021. I was very excited to experience the whole process from planting dahlia tubers and seeds to dahlia seed collection.

Pink and Yellow Dahlias started from seed indoors
Pink and Yellow Dahlias started from seed indoors

Growing Dahlias from Seed

At first, I was a little intimidated, I’ll admit. I had seen the beauty of other gardeners’ dahlias all over Instagram.

Who am I to think I can even come close to that?

But, I shrugged it off because everyone starts somewhere, and truly, the gardening community is very welcoming and supportive at large.

If it’s your first time growing dahlias from seed, don’t be intimidated! I am happy and honored to help you through the process.

Dahlia seeds and seed pods from our garden
Dahlia seeds and seed pods from our garden

Dahlia Seedlings

When planted from seed, a dahlia sprout is bright green in color and tends to have two rounded, oblong leaves. You may see a fine line down the center of each leaf. These first leaves are the cotyledon.

Once the true leaves grow on your dahlia seedlings, you may see more of a pointed and serrated edge to the leaves.

Starting Dahlias Indoors from Seed - Dahlia Seedlings in a Blue Egg Carton with Seed Coat still attached to cotyledon
Dahlia Seedlings in a turquoise egg carton with seed coat still attached to cotyledon

Sowing Dahlia Seeds Indoors

Dahlias offer breathtaking beauty in the garden or spilling over a vase. In my humble opinion, growing dahlias from seed is just as easy as growing any other flowers from seed.

I used the same exact process of using egg cartons to start seeds as I always do for zinnias, calendula, marigolds, and others.

For me, the big difference came when it was time to transplant the tiny dahlia seedlings from the egg trays to nursery pots or the ground.

Some of them had been growing for so long that they’d already created their own miniature tubers!

They were so cute and amazing to see. I happily upgraded their growing space!

Unwins Mix Dahlia Seeds I received in a seed swap in 2021!
Unwins Mix Dahlia Seeds I received in a seed swap back in 2021!

How to Grow Dahlias from Seed

Here are the exact steps I use to grow dahlias from seed in egg trays inside.

  1. Prepare an egg carton for planting. (You can use my exact process on planting seeds in egg cartons.) Cliff Notes: Poke holes, fill with soil, plant seeds, water, wait!
  2. Select the seeds from dahlias you wish to grow. We are planting seeds saved from our own open-pollinated dahlias, but you may wish to choose from a wide variety available. You can find dandy dahlias, cactus dahlias, or others. I’ve also grown Unwins dahlia mix, white ribbon dahlias, and a variety of large dahlias from seed. (I’ve only grown dinnerplate dahlias from tubers I purchased so far.)
  3. Sow dahlia seeds about ¼-inch deep. You can poke small holes in the soil or just brush it aside with your fingertip or a popsicle stick.
  4. Cover the seeds up with soil. Replace the soil lightly over the seeds.
  5. Water the soil with a spray bottle. Thoroughly moisten the soil enough to get down to the seeds.
  6. Place the trays in a sunny window or under grow lights. I love the grow rack I’ve created! First, I purchased an awesome shelving setup with a basket for supplies. Then, I ordered Monios LED grow lights.
  7. Check daily for moisture needs and progress. Our seed-grown dahlia sprouts often are some of the first flower seeds to germinate for us!
Unusual pink and white dahlia with a color block appears to be seed grown due to its unique variation
This unusual pink and white dahlia with a color block appears to be seed grown due to its unusual variation.

The Mystery of Seed-Grown Dahlias

The best beauty of growing dahlias from seed is that you never quite know what you’re going to get. (Well, maybe if you are a professional grower with a controlled environment…)

It’s amazing to plant a saved seed and see what comes of it. You may have favorite flowers that grow this way. If that’s the case, give them a name and save the tuber!

(If you live in a cool climate where dahlias aren’t perennial, be sure to save and store dahlia tubers indoors for next year.)

White Ribbon Dahlia started from seed indoors with a bee pollinating it
Here’s a White Ribbon Dahlia started from seed indoors with a bee pollinating it – Bees LOVE dahlias!


Dahlias may take 3 days to 3 weeks to germinate, depending on the type, seed quality, and growing conditions. Under grow lights with lots of eager attention, our first dahlia sprout appeared in 3 to 4 days only.

The time to maturity and blooming may vary for each dahlia depending on the variety. In general, dahlias may take 3 to 4 months to reach maturity and bloom from seed.

First consider package instructions if you’ve purchased the seeds. Otherwise, plant dahlia seeds near the soil surface, about 1/5 inch to 1/4 inch deep.

Dahlia sprouts look like what you’d imagine when you think of a seedling. Bright green rounded leaves emerge first as the cotyledon. These leaves have a line down the center. Next, pointier, serrated leaves emerge, often becoming a darker green over time.

Yes, dahlias are considered light-dependent germinators, which means their seeds need some exposure to light in order to initiate the sprouting process. Some darkness is good for the seeds, too, so try to balance the growing environment with natural sunlight or grow lights that you turn off when you go to bed.

Starting Dahlias Indoors from Seed

Now that I’ve had some experience starting dahlias from seed, I am hooked! I love the mystery of what each new flower will look like.

I also enjoy the same journey with zinnias, as I am working on a zinnia flower breeding project as well!

Do you have any awesome dahlias you’ve started from seed? Love to hear your stories!

Also, feel free to ask any questions or share any other tips you may have. We love hearing from you!

Happy Gardening!

05.15.23 – Updated to freshen up content, add FAQ section and new photos plus updating alt text. Improved spacing and linked to zinnia post. Updated date from 01.05.22 due to substantial edit. Updated amz links to no follow and all links to open in new tab.

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  1. This is a great article thank you after reading this I don’t feel as nervous growing dahlia seeds lol. This is my first time and your article helped a lot!!!!

    1. Hi Jennifer, thanks for your kind and amazing comment – it means so much to me hearing that my article helped! I loved growing dahlias and can’t wait to try them again this year. I wish you so much luck and hope they grow beautifully for you. Thanks again for taking the time to drop a line. Happy Gardening!

  2. Thank you for your dahlia seed post! I collected dahlia seed last year for the first time and I’m excited to give it a try!
    I’ve read that LED lights need to be kept further away from the emerging/growing seedlings. What is your experience with this?
    Thank you!

    1. Hi Barbara! Thanks so much for your note – so happy you’re growing dahlias from seed this year! They were one of my favorite things to grow last year. I kept my dahlia seedlings on the same racks / distances from grow lights as the rest of my seedlings. I started them with the lights just a few inches above the trays and only raised the lights as the plants grew. How’s it going for you? Best wishes for your garden this year!

  3. THANK YOU KATE! I’m was nervous I was doing something wrong until I read this article. I germinated my seeds first (wet paper towel in a ziplock on the fridge), then planted them and I’m not seeing anything happen. But I now know I have to give them some more time. I’ll continue to wait with my fingers crossed.

    1. Hi Jennifer, great hearing from you and I am so glad the post helped! It can definitely take some time. Did you see the seeds sprouting before you planted them? I hope you will have beautiful dahlias blooming in your garden this year. 🙂

  4. newbie here. Will a dahlia planted from seed create a tuber? Also, Will a dahlia seed create a dahlia similar to the plant the seed came from?

    1. Hi Diane, welcome to such an exciting new journey! Growing dahlias from seed is very rewarding and fun in my personal opinion! Yes, they will create a small tuber even the first year from seed! It’s awesome and definitely gives a sense of accomplishment. The appearance will depend on what crossed with the mother dahlia to create the seed. You may find different color blends or petal shapes, fullness, and other unique traits. Love to hear how this goes for you! Best wishes with the experience!

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