This Is A Dahlia Tuber

Receiving your Dahlia Tubers

Dahlia tubers are like people in that they come in a wide range of sizes, from small, narrow, slightly wrinkled* ones, to big, round, plump ones.
It can be a shock for new Dahlia growers to compare two varieties: the smaller one looks like a reject compared to the bigger one!
However, this range of sizes is completely normal, and in many cases, a variety with the smaller tubers grows into a bigger plant than a variety with large tubers. 

*Wrinkles on a dahlia tuber are normal if the tuber is firm. If the tuber is soft, then it's almost certainly rotten, diseased, or has been out of the ground for too long and should be discarded.

Dahlia Tuber Anatomy

A dahlia tuber consists of three main parts, from top to bottom, which have been colour-coded:

(Images courtesy of Summer Dreams Farm in Michigan, USA, from their excellent Dahlia Tuber Splitting Guide)

• Pink: The crown (or head) at the top, which has "eyes", where all the shoots will come from. These little bumps can be a bit hard to see until they start swelling prior to sprouting. 
• Purple: The neck, connecting the head to the body.
• Green: The body, which only stores starch and does not produce any leafy shoots, only roots. Most Dahlias will have several bodies per crown, so losing one doesn't matter. 

Therefore:

1. A tuber with no eyes is useless and can be thrown away, no matter how big it is.
2. A crown/head with an eye and a small scrap of tuber body still attached, even just the neck, will grow. In year one, it will be a smallish plant, but in year two it will look normal.  
3. If the eyes have begun to sprout before delivery and their shoots get knocked off, this is not a problem: the eye will make more shoots.

Below is an image of an eye sprouting, with the black line marking the point where the neck ends, and the crown begins: if you were to cut the tuber there, the eye would still grow, just more slowly at first.

And here is what happens when a shoot is broken off (you can see the round scar in the centre of the image): it grows a new one right away.

(Photo used with permission from Clara Joyce Flowers.)

What do I do if I receive my Dahlias with some Tuber Bodies broken off? 

Every so often, a customer receives a dahlia tuber with some of the bodies separated from the crown.

Below, you can see the lines marking the place where the crown meets the neck.

If you were to cut off all the necks and throw them away with their bodies (we don't recommend it!), the remaining crown would still grow shoots. 

 

So, you always plant the crown as normal with its remaining tuber bodies attached (if any).

Next, inspect the broken off tuber/s to see if there is a piece of crown on top with an eye.
The eye will only be on the crown end, on top of the neck, never anywhere else on the tuber body (so it's not like a potato tuber in that sense, which can have eyes anywhere on their tubers). 

• If you find an eye on the tuber, that's great - you now have two plants! 
• If there is no eye on the tuber, throw it away. It hardly matters to the Dahlia: it's the equivalent of snipping off a piece of root from a tree or shrub. 
  You probably won't even notice the very slight reduction in the Dahlia's size during its first year, and in the second year it will have replaced the lost tuber with a fistful of new ones.