Growing New Plants from Individual Dahlia Tubers

By Sarah Battersby

/Apr 15 2016


Single dahlia tuber planted in grow mix.

Single dahlia tuber planted in grow mix. The eye is the tiny dark spot in the protruding part at the top.

At the Peterborough Garden Show recently I was surprised to see samples of new dahlias growing in pots looking like fingers stuck in the ground. In my dahlia growing experience I’ve always planted an entire cut-off stalk surrounded by several tubers in a mass, usually purchased in a bag with tubers and sawdust. However this was something new I’d never seen. A dahlia specialist at a garden show gives you the opportunity to see a wider variety of species, as many specialists will have myriad varieties. The tubers they provide are individual dry tubers, harvested last spring, cleaned and trimmed so they are stored singly. And they do look a little bit like fat fingers.

The important thing about each dahlia tuber ‘finger’ is that it must have a little piece of original stem attached which contains the growing “eye”. Dahlia tuber eyes are similar to the eye that you see growing on a potato tuber, except they tend to be small and harder to notice. The grower pointed it out to me on the tuber I bought. Very small, but unmistakeable once you see it: a small round swelling on the tuber around the place where it joins the stem. Any other tubers that fall off a purchased dahlia stem without this eye are useless. The tuber provides the food source for the plant, but nothing will happen without an eye, as it is the growing tip.

Once you know this you can treat the dahlias that you buy differently, cutting off tuber sections (that contain a piece of stem and an eye) and making more plants. I did this with a traditional package of dahlia tubers I bought. Some of the tubers had detached, and most had no eye, (boo) but one, luckily did! Now I have two dahlias growing instead of just one. If you look closely at the tuber in the picture above you can see a dark spot in the protruding section at the top. That is the eye. Once it has started growth, I will plant and bury the tuber and some of the stem. The grower also told me that you can mound the earth up around the stem for better growth as more tubers will grow from the stem.

If you want to learn more about growing dahlias you can take a course this month, given by local flower grower Sarah Nixon of My Luscious Backyard. She is giving a workshop called Dahlia Mania on April 24th that tells you everything you need to know about growing dahlias. So buy that bag of dahlias and learn how best to grow them from a local expert. Sarah Nixon is a fantastic local flower grower who uses many front and backyards in Parkdale for her sustainable flower business.

Info about the course:

All materials for potting up will be provided. Bring your tubers and we will do it together.
Tubers will be available for purchase.
On April 24th, from 2-4 pm at my home in Parkdale.
Cost: $45. + hst. Payment will book your spot and is non-refundable.
Please be in touch to register!
mylusciousbackyard@gmail.com