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Growing Hydroponic Dahlias From Seed

Growing Hydroponic Dahlias From Seed

Growing hydroponic Dahlias from seed is super easy. The beautiful showy Dahlia flowers have to be one of my absolute favorites. I purchased five plants this year from a local nursery and paid $10 per plant! That’s right, $50 for only five plants. I think that’s quite expensive, so this is how this experiment began.

Hydroponic AeroGarden Dahlias Red

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I wanted to know if growing hydroponic Dahlia flowers from seed is possible so I purchased a couple of bags of seeds and got started.

I’m not a professional gardener, actually quite the contrary. I struggle with flowers which is why I was hesitant to pay $10 for only one. As I’m planting each one I’m singing the song, “Go little rockstar…”. I had recently purchased two hydroponic growing systems for my counter so I decided to grow Dahlias from seed and see what happened.

Can You Grow Dahlia Flowers From Seed In A Hydroponic Growing System?

Yes, Dahlia seeds will grow in hydroponics. I’ve grown several in my hydroponic growing system. But here’s what you need to know. The growing sponges need a bit of modification.

I decided to plant two seeds per pod to increase my odds of having one be successful. As I was planting them in the growing sponge, I noticed the tip of the seed was sticking out of the sponge.

The first time I planted Dahlias in hydroponics, I ignored this. The seed germinated, but the stem had a tiny bit of fuzzy white mold. The plant did not survive.

The next time, I took a small paring knife and cored out the sponge just a bit so that the seeds could sit down in the sponge a little better. I placed the plastic germination cup over the top and waited for my Dahlias to germinate.

How Long Does It Take For Hydroponic Dahlias To Germinate

I had successful Dahlia germination in my hydroponic gardens in about 2 – 3 days. As soon as I saw green leaves sprouting, I removed the little clear plastic cover.

Once the Dahlia sprout is about an inch tall, you can cover the rest of the top of the sponge with a bit of aluminum foil to keep the sponge from molding. This is a common issue with hydroponics.

Some companies sell sprouting sponges with a paper cover but it’s more expensive and the foil works great and saves money. Aerogarden sells the seeds with covers if you’d like to use those.

Growth is steady but slow for the first 2 weeks. The second two weeks is when the magic happens and all of a sudden they really shoot up and get tall.

Dahlia Nutrients

I’ve been using the nutrients that came with the iDOO garden for my Dahlias. I use the same nutrients for the AeroGarden Dahlias as I do for the iDoo Dahlias. Both systems are growing Dahlias equally in size.

Be sure to add more plant food when you are adding water to the system and also if you completely change the water.

hydroponic AeroGarden Dahlias Pink

A Note About Planting Dahlia Seeds

I didn’t realize that the only way to get Dahlias that look exactly like your original plants, you have to propagate them by division which means you have to separate a tuber from an existing plant. The tuber is a bulb-like root that is long and skinny rather than round.

If you grow dahlias from seed, the new flower will create an entirely new variety and won’t look exactly like the original plant. I thought that was interesting but it makes sense.

The same thing happens when I propagate snake plants. The distinct pattern in the snake plant will not carry over to a plant I’ve propagated from a cutting in water. To retain the leaf pattern, I would need to propagate by division.

Will They Flower In The Hydroponic System?

Dahlias get quite large and common sense made me think that they would outgrow the system before they bloom. After one month, the plants were hitting the light and I had to move them outdoors.

The good news is, that they are doing well after moving them.

Do Dahlias Like Full Sun?

I have Dahlias in full sun and they are doing well. Although, when you move Dahlias from hydroponics to soil, you will need to acclimate them first.

Hydroponic AeroGarden Dahlias purple and white

Plant your Dahlia in a plastic pot with drainage and move it close to a window for a few days to get it used to the soil and natural light. It’s going through a big change being moved from growing in water to the soil.

After a few days, move the Dahlias to a shaded area to get them used to the new temperature. I like to leave mine in the shade for a few days and then move them to a place where they get part sun, they finally to full sun. We get 100-degree temperatures here.

They will likely go through a bit of shock but you want to slowly move them to a full sun area before planting them in the ground. It’s a bit of a process but it works.

More About Dahlias

I say it over and over again, “I’m not a professional”. I’ve found a couple of great articles about growing Dahlias that I think would be helpful for you. You can learn more about how to plant, grow and care for Dahlias and also more about how Dahlias change when planted from seed.

I appreciate you sharing this gardening experiment with me. Please drop a comment below if you have any tips about growing hydroponic Dahlias or getting Dahlias to bloom in a countertop garden.

Be sure to stop by and visit my other blog where I share home decor, crafts, and DIY projects at Hootshack.

Happy gardening,



Sunday 9th of April 2023

Thank you! I love dahlias but am in Arizona desert where I have killed more of the poor plants than one can imagine. So I'm thinking outside the ground.

Denise Reeser

Tuesday 24th of October 2023

You can start them indoors and then have them ready for outdoor planting. Try a shady area!