For years I walked away from the section in the garden center where they were selling dahlia tubers. Yes, the flowers looked pretty. The colors were varied and the tubers seemed easy to plant. But, I shied away from having to dig the tubers up each fall if I wanted to continue to grow the flowers. It seemed like so much work. I didn’t have any place to store them and the cost of the individual tubers seemed high.

Literally, years went by. More dahlia varieties came on the market and the flower seemed to be making a comeback in popularity. I decided to purchase a few tubers and a packet of seeds to plant. After that first season, I became hooked. I couldn’t believe how easy dahlias were to grow. And I was amazed at the massive amounts of flowers they provided for my cutting garden.

Because of my garden zone, I knew I would need to dig the specialty tubers up in the fall. But I discovered that it wasn’t a difficult process. It actually felt like a treasure hunt. How could those few tubers I bought turn into a bucketful? But the biggest surprise was the plants I grew from seeds. They grew in so many different styles and colors… a kaleidoscope in my garden. They also produced tubers that I couldn’t resist saving.

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Dahlia Basics…

Dahlias are an tuberous flower that can grow 5-7 feet tall. The flowers come in a variety of sizes from tiny pompom size to massive dinner plate size. You’ll find a variety of flower forms from very symmetrical to lacy-leafed patterns. And the variety of colors range from white, pink, yellow, orange, reds, and even shades of purple. With so many different variations your garden can be loaded with dahlias in all shapes, sizes, and colors.

There Are Three Main Ways to Grow Dahlias…

Tubers

The easiest way to grow dahlias is to purchase dahlia tubers. It’s hard to believe that such beautiful flowers can come from a tuber that looks like a miniature potato. You can buy tubers online or at your local garden center. When you purchase a tuber, you know exactly what flower you’re getting… what it looks like, the size and shape of the flowers, and the height of the plant. A tuber grows a genetic clone to the original plant. This is how most people plant their dahlias.

Buying tubers is a slightly more expensive way to grow dahlias. Tuber prices often start at $5 per tuber and can go up to $20 or more. Most tubers run from $5-$10 depending on your source. Each tuber produces one plant. Purchasing tubers is a good way to grow specific types of dahlias in your garden.

Seeds

Growing dahlias from seeds is a less expensive option. Typically for $3-$6, you can grow a flowerbed full of beautiful dahlias in a variety of colors and styles. However, you won’t know what you’re going to get with seeds. What grows will be a mystery. You plant the seeds and wait to discover what beautiful blooms will grow from that seed packet.

Not all dahlia types are common for seed growing. The more open flowers, with a large center, are easier to pollinate and therefore more prolific. The tight flower heads, where pollinators have difficulty getting to the center, will mean less seed production.

Cuttings

The third way to plant dahlias is to take cuttings from your already growing plants. Allow the cuttings to grow roots and plant them in your garden. The flowers will be identical to the original plant. So if you have a costly dahlia variety that you want more of, then this is a great way to increase your flowers during the growing season.

Why Grow Dahlias From Seed…

I have grown dahlias using all three methods. Each year, I purchase new tuber varieties so I can expand my plant selections. But because of the cost of tubers, I limit my new purchases to just 3 or 4 each year. Then I supplement with seeds. Growing from seeds adds to the flower varieties and will provide abundant flowers for my bouquets.

One of the unique things about growing dahlias from seeds is that you never know what to expect. Unlike growing from a tuber where you’ll get an identical plant, when you grow from seeds, the flowers will not necessarily be identical to the original plant. As the flowers grow, the seeds that form can be cross-pollinated with different plant varieties. Each seed on a plant, even from the same flower head can be pollinated with different pollen. That means that each seed could have slight variations in colors, shapes, and sizes.

This is how new dahlia breeds are being created each year. Breeders specifically cross-pollinate plants to try to get fantastic new varieties. Then the tubers that form can be used to propagate more of that same beautiful flower.

You don’t have to be a breeder to grow a fantastic new variety from the seeds you save from your dahlia plants. Just allow the natural pollination process to create something unique and special. That’s why growing dahlias from seed is so exciting. The bees, bugs, and butterflies do the work of pollinating. Then you save your seeds and plant them next year. Who knows what wonderful flowers those seeds will grow into?

This year I’ll try my hand at growing my first batch of dahlia seeds that I grew and saved from my garden. I’m looking forward to seeing if I have any unique flowers develop that I can continue to propagate. I’m not a flower breeder and I don’t expect to grow the next Cafe au Lait. I just love the idea that I can grow something special to share with friends and family.

Steps to Grow Dahlias From Seed…

Step 1

Purchase dahlia seeds of your choice. Seeds are easier to come by in the spring. Before planting you will want to prepare your beds. Mix compost and steer manure into your soil. Add a generous dose of regular fertilizer to boost plant growth as well.

Step 2

You can plant the seeds directly into your garden beds or plant in starter pots if it’s still too early to plant directly into the ground. Dahlias should be planted outdoors after the last frost date in your area. They’re not cold hardy and can’t survive a drop in temperature. Be sure to plant your dahlias in full sun where they will get at least 6 hours of direct sunlight.

Plant your dahlia seedlings about 12 inches apart. Rows should also be about 18 inches apart. If you started your seeds directly in the ground, thin your seedlings to this space. These are rather large plants so they need room to grow.

You can also plant your dahlia starts/seeds in mixed flower borders or even in pots. Just make sure that you have enough space for the plants to grow. If planting in pots, use large size containers such as a 24-inch terracotta pot, wine barrel or large galvanized container.

TIP : When thinning, dig up any extra seedlings and either find a spot elsewhere to plant them or transplant into pots to share with friends and family.

Step 3

Because dahlias can grow very tall, they’ll need to be staked to keep them from blowing over. While your plants are still small, add support stakes to them. Place a 5-6 foot tall stake about 6 inches from the plant or you can stake the corners of your flowerbed.

As the plant grows taller, tie the plant to the stake or rope off the area around your bed. You should tie the plants to your stakes about every two feet for the best support. If you are roping off the bed, use study twine, rope, or even wire and firmly attach it to the four corner posts so your plants will be held upright.

Step 4

If you want to try your hand at growing your own seeds, then toward the end of the growing season, allow some of your best flower heads to go to seed. Allow them to remain on the plant and slowly dry out. Look for seed pods that have lost their leaves. You can actually remove any remaining leaves from the drying flower head to help the drying process along.

Once sufficiently dried, harvest the seed pods that formed and save them for next year. In order to prevent the seeds from molding, open the pods and leave the seeds in a container that allows air circulation. If you want more information on saving seeds then check out this post… How to Save Flower Seeds From Your Garden.

Resources…

While not a dahlia expert, I’ve developed a love for these flowers. If you would like more detailed information about growing dahlias, especially from seeds, check out these resources.

• Floret Farm’s Discovering Dahlias by Erin Benzakein
• Dahlia Breeding by Kristin Albrecht
• The Joy of Dahlias by Linda van der Slot, Katja Staring, and Marlies Weijers

I’ve become a little passionate about growing dahlias. Now instead of shying away from the dahlia section at the garden center, I delight in seeing what they have. I’ll usually select some specialty tubers to plant. But I always purchase a packet of seeds because it’s so easy to grow dahlias from seeds. And I love the surprise of discovering what dahlia plants grow. Don’t walk by the dahlia section and wait for years to plant dahlias in your garden. I dare you to give them a try. Before you know it you’ll be hooked as well.