Do you divide your Dahlia tubers or leave them as one big clump? It is a question many of us have pondered, especially when we are new to Dahlias. Luckily I have been growing them for many years, so let me help you out.
Growing Dahlias From a Single Tuber
Yes, Dahlias will grow from a single tuber, as long as it has all of the pre-requisite parts needed for growth.
These are an eye, a neck, and the body of the tuber.
As long as your tuber has these three parts and it has not shriveled or rotted, it will grow.
Does the Size of the Tuber Matter?
Up to a certain point, no, it does not matter.
Even small tubers can grow and create vigorous, healthy plants with many flowers in a single season.
At the most basic level, a Dahlia tuber is a bundle of stored energy; its reason for existing is to allow the plant to root and get going.
After this point, it is unnecessary as the plant can take up all the energy it needs through its newly grown roots.
So as long as the tuber has enough energy stored within it to get the plant started, then the size doesn’t matter.
That is why I mentioned that size doesn’t matter to a point. If the tuber is tiny, say less than a AA battery, it may struggle; anything above this size will be fine.
It is also worth mentioning that different varieties of Dahlia have different sizes of tuber. Some are larger, and others smaller.
There can be quite a bit of variation between the largest and smallest. So if all of your tubers from one variety are small, it may just be how that variety grows.
What Happens if You Don’t Separate The Tubers?
Your Dahlias will continue to grow from the large tuber group. They will continue to add more tubers to the root structure as they grow. After two years, they get really large and difficult to dig up.
How Many Dahlias Can You Grow From One Tuber?
If you take cuttings from a Dahlia tuber, you can expect to get anywhere from 5-10 cuttings from a single tuber.
The amount of successful cuttings you get depends on your skill, knowledge, and equipment. A good rate would be around 90% success.
So you could expect to grow nine separate plants from a single tuber!