Growing Dahlias From Seed

Learn How To Grow Beautiful Dahlias From Seed

Have you ever tried growing dahlias from seed? Traditionally dahlia flowers are grown from tubers, but did you know that you can also grow dahlias from seed? I prefer to grow most of my dahlias from tubers because I know exactly what they will look like when they bloom. However, I also find it to be fun and exciting to try growing some dahlia flowers from seed as they will produce new varieties I haven’t seen before. When you grow dahlias from seed, you are essentially growing new plants with new and unique blooms.

Affiliate Disclosure: Some of the links on this page may contain affiliate links. That means that if you make a purchase through one of these links, I may receive a small commission at no extra charge to you. Thank you in advance for your support of my blog!

What is the difference in growing dahlias from seed vs dahlia tubers?

Traditionally people have multiplied their dahlia tuber stock by dividing their dahlia tubers. This method produces new plants that are identical to the parent plant or “mother tuber.” Growing dahlias from seed is very different from growing dahlias from tubers. When you grow dahlias from seed, no two plants will ever be the same! That’s right, by growing dahlia flower seeds, you are actually creating a new variety of dahlias that’s never been grown before.

When you leave a dahlia flower on the plant, it will eventually go to seed. The flower head will create a seed pod that will produce seeds that you can then grow the following year. Each seed contains it’s own DNA and will grow a new and unique variety. These seed pods are typically harvested at the end of the growing season to allow the seed heads to fully mature and produce ripe seeds. Then after harvesting the seeds, you store them over winter and grow them the next spring.

Dahlia flower seeds get their genetic makeup from the seed parent as well as from the pollination of bees. That’s right, the bees and other garden pollinators actually play a huge role in determining what your dahlia seeds will eventually grow. The bees carry pollen from one dahlia plant to the next and actually modify the genetic make-up of the dahlia seeds. Most open pollinated dahlia seeds will grow single or semi-double blooms with an open-center. Many breeders will either eliminate open centered dahlias or hand pollinate their dahlias to increase their chances of producing a fully double dahlia.

There are some amazing dahlia breeders like Kristine Albrech of Santa Cruz Dahlias who specialize in dahlia breeding. Kristine focuses on hybridizing new dahlia varieties from seed. If you are interested in learning more about breeding dahlias, you should check out Kristine’s book.

Instructions for growing dahlias from seed

There are several reasons you may want to consider growing dahlia flowers from seed. Growing dahlias from seed is much cheaper and more affordable than buying a pack of dahlia tubers. You can buy a packet of seeds for $5-20 dollars whereas a single dahlia tuber will run you $8-35 dollars! For the cost of one dahlia tuber, you can grow many dahlias from seed that will produce beautiful flowers their first year! If you save your own seed, you can grow your own new dahlia varieties the following spring!

Another reason to grow dahlias from seed is for the sheer excitement of the unknown. It’s exciting to watch a plant grow from seed. You will find yourself waiting in anticipation, wondering what color, shape, and size dahlia you are growing. How neat is it to grow a variety that no one else has?!?

What do dahlia seeds look like?

Dahlia seeds come from the inside of a ripe seed pod. Inside each seed pod are the dahlia seeds. Most home gardeners do not collect their own dahlia seeds. If you decide to grow your own dahlias from seed, you will see that the dahlia seeds are thin, black, and under ½ inch long.

Here is what a handful of dahlia seeds looks like:

Where to buy dahlia flower seeds for growing?

If you decide that you want to grow your own dahlias from seed, you can either purchase your seeds OR collect your own!

At The Flowering Farmhouse we actually sell a limited quantity of seeds collected from our farm! Some of my other favorite farmers who sell seeds includes:

–The Farmhouse Flower Farm

–Triple Wren Farms

–Coseytown Flowers

And of course some of the larger seed companies also sell dahlia seeds. You will find that most seeds from the larger garden centers produce open centered dahlias. Click here for a list of my favorite seed suppliers.

–Floret Flowers offers a Bee’s Choice Mix of dahlia seeds. I have grown dahlias from this seed packet and let me tell you, I’ve never seen so many happy bees! This mix of dahlias produces a wide range of varying shapes and sizes. Most of these dahlias will be open-centered and single bloom dahlias.

–Johnny’s Selected Seeds offers a Giant Hybrid Mix of dahlia seeds. This mix of dahlia seeds is supposed to produce a mix of 3-5’’ double, semidouble, and single blooms.

When you should plant dahlia seeds

When growing dahlias from seed, you want to plant dahlia seeds indoors about 6-8 weeks prior to your last frost date. If you do not know your growing zone’s last frost date, you can find it here. This will give your dahlia seeds time to start growing and to be ready to plant outside. You do not want to transplant your dahlia starts outside until all danger of frost has passed.

How To Plant & Grow Dahlias From Seed

Once you decide to grow dahlias from seed, you will want to start your dahlia seeds indoors. Start your seeds indoors 6-8 weeks prior to your last frost date. This will give your dahlia flower seeds enough time to get growing so that they can flower in the summer months. Dahlias will bloom until your first frost. It takes about 100-120 days for the seeds to produce flowers.

There are several ways you can get your dahlias seeds to germinate. Dahlia seeds have pretty poor germination rates with 20-80% germinating. The most reliable way for getting your dahlia seeds to germinate is with paper towels. The other method involves direct seeding into cell plugs. For best results, I recommend germinating your seeds with paper towels.

You Can Use Paper Towels To Germinate Dahlia Seeds When Growing Dahlias From Seed

For the first method, start by taking two wet paper towels and placing the dahlia seeds flat on one. Cover the dahlia seeds with the other paper towel. Place the paper towels and seeds inside a zip lock bag. Lay the zip lock bag flat on the top of your refrigerator. Leave the seeds for 3-5 days. After that time, start checking the bag daily for signs of germination. Once the seeds have germinated, carefully plant the seedlings in a seed tray. Place the tray of seedlings under grow lights. I check the seeds starting at day 3 and plant the ones that have germinated. I then continue to check daily for about 2 weeks for germination. After that point, I toss the ones that have not germinated.

Planting Dahlia Seeds In Seed Trays Under Grow Lights

The other method is to plant your seedlings directly onto your seed trays. Fill your seed starting trays with seed starting mix. Poke a small hole in each of the seed cells. Take dahlia seeds and sow seeds, with one in each seed cell. Bottom water the seed tray and cover with a clear acrylic dome. I like to place my seed tray on a heat mat and underneath a grow light. This ensures that the soil is warm enough for germination. Dahlia seeds need a warm location to germinate and grow. Seedlings should emerge within 3-5 days.

I did an experiment this winter and tried starting dahlia seeds using both of the methods above. I actually found that the dahlia seeds sprouted in about the same amount of time using both methods. However, the seeds that were germinated underneath grow lights in the cell plug flats actually grew better initially. Within a week of both being planted in cell plugs, it was hard to tell the difference in either method. The only downside to direct sowing is that you may end up with empty seed cells because of low germination rates with dahlia seeds.

When To Transplant Your Dahlia Seedlings

Once your young seedlings have true leaves growing, you will want to transplant them into larger containers. This is important so that your dahlia plants do not become root bound. Continue growing your dahlia plants indoors (or inside a heated greenhouse) until all dangers of frost have passed. Once the risk of frost has passed, you can safely plant your dahlias outdoors in a sunny spot with well-drained soil. Be sure to space your plants 12-18” apart to allow for enough space for the tubers to form. For more detailed planting instructions, be sure to visit my post on How To Plant Dahlia Tubers.

If you live in a growing zone with a longer growing period, you can also direct seed your dahlia seeds into the garden. For this option, your soil needs to be at least 65-70 degrees F. You also want to make sure that all dangers of frost have passed.

When will my dahlia seeds bloom?

It can sometimes feel like an eternity waiting for your dahlia seeds to bloom with flowers. Dahlia seeds usually take 100-120 days to bloom. Depending upon when you sow your seeds, you will likely see your first dahlia flowers in mid-July to early August.

Will dahlia seeds turn into tubers?

At the end of the growing seasons your dahlia seeds will have produced viable dahlia tubers that you can dig up and save for the following season. These dahlia tubers will produce identical plants to what was grown this year. Because dahlias are tender perennials (or annuals in some zones), you should dig up and store your tubers over winter. Be sure to check out my blog post for tutorials on removing and storing your dahlias over winter.

Do You Save Your Dahlias Grown From Seed?

Each summer I always go through my dahlias that were started from seed and decide which ones to keep and which ones to toss. In the past I have grown between 50-75 dahlia plants from seed each year. Most of these have produced open centered, single flowers that the bees love, but they are not excellent cut flowers. Typically I find that I keep about 1-5 varieties each year that I’ve grown from seed. If these plants produce quality dahlia blooms again in their second season, then I can name them and grow them a 3rd season to multiply and add to my tuber collection.

Ready to start growing dahlias from seed?

Did this inspire you to try growing your own dahlias from seed? There’s something so rewarding about growing plants from seeds you start! You can also save lots of money by growing your own dahlias from seeds. Plus, how neat is it that you can have dahlia varieties growing in your own cut flower garden that are different from any others in the entire world!

To learn more about dahlias, be sure to visit my detailed post, A Beginner’s Guide To Growing Dahlias!

I hope this blog post has inspired you to try growing your own dahlias from seed. If you try growing dahlias from seed, I’d love to hear how it goes! Who knows, maybe your dahlias seeds will become your new favorite flowers! And don’t forget to PIN this blog post to Pinterest so you can easily come back to it later.

Happy Gardening!

Get in the know.

Sign up with your email address to receive news and updates.

Subscribe

Thank you for subscribing!

Additional Dahlia Blog Posts You Might Enjoy:

5 Steps To Divide Dahlia Tubers

The Flowering Farmhouse

09/25/2023

If you’re new to dahlias or you’ve never dug up your dahlia tubers before, this post will help you with five steps to divide your dahlia tubers for next season.

Continue Reading 5 Steps To Divide Dahlia Tubers

A Beginner’s Guide To Growing Dahlias

The Flowering Farmhouse

09/25/2023

A beginner’s guide to growing dahlias. Everything you need to know to successfully plant, grow, and care for your dahlia flowers in your garden.

Continue Reading A Beginner’s Guide To Growing Dahlias

Understanding Dahlia Diseases & Dahlia Viruses

The Flowering Farmhouse

09/11/2023

Learn how to tell if your dahlia plant has a disease and what to do if it does. Dahlia disease and viruses are unfortunately common and if you grow dahlias long enough, you are likely to come across a virus or diseased plant.

Continue Reading Understanding Dahlia Diseases & Dahlia Viruses

How To Plant Dahlia Tubers

The Flowering Farmhouse

02/09/2021

A Beginner’s Step By Step Guide For Planting Dahlia Tubers | Learn how to easily prepare and plant your dahlia tubers so that you have gorgeous dahlia flowers this summer!

Continue Reading How To Plant Dahlia Tubers