Every single dahlia you love was once a seedling in a hopeful gardener’s dahlia patch.
Dahlias are really rewarding to grow from seed. They’re easy to start, they bloom within a few weeks, and if you keep them harvested, they’ll bloom their sweet little heads off all summer long for you. But dahlias grown from seed are significantly different than dahlias grown from tubers or cuttings. In this article, we’re going to unpack these differences and I’m going to give you my best advice for getting the most from your year 1 dahlia seedlings.
You can grow dahlias from seeds?!
First things first: If you didn’t know dahlias could grow from seeds, you’re not alone. I’ve met plenty of experienced dahlia gardeners that only grew their dahlia plants from tubers and/or cuttings. They either thought that dahlia seeds weren’t viable or didn’t even realize ripened blooms would make seeds.
When trying to understand dahlia seeds, first of all it helps to keep in mind that almost every plant you see growing in the world around you is trying to reproduce itself. Whether by spreading rhizomes, waving velcro-covered seed pods around until they stick to your pants or an animal’s fur, attracting birds to eat their delicious fruit and “drop” their seeds everywhere birds “go,” creating tubers to clone itself, attracting forgetful squirrels to plant nuts, or any number of creative methods, plants are reproducing all around us.
Many plants have multiple ways of reproducing themselves, and it is fairly easy to force reproduction on many different kinds of plants by air-layering roots, taking herbaceous cuttings, or dividing the plants.
The dahlias we commonly cultivate in gardens today naturally reproduce themselves in two ways at once: they produce bountiful flowers that (when pollinated and properly ripened) make beautiful seeds, and they also produce abundant tubers when grown well.
The Main Difference Between Dahlia Tubers and Seeds
There is one major difference in these two methods, however. The dahlia tubers will produce copies, or clones, of their “mother” plants, but the seeds will not. Instead, the seeds will produce an amazingly diverse collection of unique blooms. The new seeds are hybrids of the plant they developed on (simply put, their mother), and the plant whose pollen an insect carried to the mother (simply put, their father). The different seeds on a seed-head can have many different “fathers,” so each seed from the head can look wildly different!
Growing Dahlias from Seed is How Hybridizers Find New, Amazing Varieties
Anyone who grows dahlias can save dahlia seeds, but experienced growers tend to develop their unique methods for saving and collecting dahlia seeds. Their specific methods yield the fantastic results we see in their hybrids.
If you’re new to saving your own seed, our two best tips are:
- Remember that your open-pollinated seedlings will carry the most dominant traits of the dahlias in your garden. For example, you’re less likely to get pastel double flowers if you also have a collarette collection or many red or bright yellow dahlia blooms in your garden. (You can do a fantastic deep dive into the science of this from this amazing book by Kristine Albrecht of Santa Cruz Dahlias!)
- Don’t try to save your dahlia seeds too early. Here at Triple Wren, we don’t let our dahlias go to seed too early in the season. We want to enjoy the most lush, bountiful displays of blooms first! If you don’t harvest your blooms or deadhead spent flowers through the season, leaving your dahlias to set seed early on, then the plants are triggered that they’ve finished their goal of reproducing and will begin to shut down for the season. They’ll slow their foliage growth, tuber growth, and bloom production as they literally “go to seed.”
If you’re wanting to save dahlia seed from your garden this year, we recommend waiting until mid-September to start letting part of your cut flower garden dahlias go to seed. This way you get to enjoy the flowers all season, your tubers will be well-developed, and you’ll still have plenty of seed. Watch our newsletter later this summer for a demonstration on how to save you dahlia seeds! (In the meantime you can get a sneak peek here.)
Would you like to learn how to hybridize your own dahlia varieties?
If you’d like to learn more about how to hybridize your own dahlia varieties, we have created a Hybridizer Hub over in The Garden just for you. We have topics that include:
- How to decide whether a seedling is a “keeper” or not
- Genetic traits to consider
- Timeline for seedling observation
- What to record about your observations
- Bees vs. Intentional Pollination
- Seed Collecting
- How to Seek Outside Validation for Your Seedling
- and more!
We are adding valuable information to the Hybridizer Hub frequently! If you’re interested in learning more about hybridizing dahlias, consider joining The Garden today!