A Different Way to Grow Dahlias


The traditional way to grow dahlias is either from tubers or cuttings. Both methods rely on duplicating or cloning a particular flower, making more of the exact same one. We cover both propagation methods in detail in The Business of Growing Flowers Module 8: Growing Techniques to make you Profitable, and they are certainly essential to developing a stock of fabulous saleable varieties. But there’s also another way of growing dahlias…

Every year I grow dahlias from seed, just for the joy of it. Dahlias don’t grow ‘true’ from seeds, they will create a new variation from the genes of the original plant and the one it is pollinated with. You don’t know what you’ll get when growing from seed, it’s a real lottery. Hybrid dahlia seed is sold by most seed companies and you can also save seed from plants you particularly like.

Now’s the time to collect the seed, before it gets too cold or damp and the seeds rot on the plant. The seedhead masquerades as a bud, it’s a similar shape and size but has more of a pointed shape than a bud. Either find some seedheads or let a flower go to seed (I know, it goes against the grain to let a flower go over without being cut and sold) then collect the seeds once the head ripens and goes brown. Store the seed in a cool dry place until the spring.

In March or April, plant the seed in modules, trays or small pots and put in a warm place. They will germinate speedily and grow fairly quickly so I tend to sow seed into small pots then they don’t need to be moved on.

Once they’re through the seedlings will grow on nicely so long as they are

  • kept moist - dahlias don’t like to dry out

  • frost free - any sign of frost will kill them dead

  • away from slugs - dahlia seedlings send out a siren call to slugs, they are a delicious treat and slugs can smell them from miles away

You will need a sheltered spot to grow the seedlings on until it’s safe to plant out, once your last frost date has passed.

Then, it’s just a waiting game to see what you get. My seed grown plants were the first dahlias to flower this season, easily beating the tubers and cuttings into bloom. I’ve been delighted by the new varieties, great colours, lovely shapes and long, strong stems. Some of the seeds I collected last year have come true to the original plant, a dark red single flower called Mexican Black.

I’ll be keeping all the seed grown plants as tubers and hopefully will propagate more plants from them in the Spring, as well as collecting more seed for surprise tubers next year. It’s the never ending possibilities and new plants for very little money, what could be better!