It's late November and I finally finished preparing my dahlia tubers for winter storage. I had tubers from ~140 plants to dig, wash, dry, clean and divide this year. I dug them all back in the middle of October washed all dirt off. Here is the picture showing 1/3 of my tuber harvest right after washing.
Then tubers were kept in the outside storage until I was ready to divide them. I prefer to divide tubers in autumn. Divided tubers take much less storage space. Removing of stalks and old tubers significantly decreases rotting of divided tubers. And of course dividing of so many tubers takes time which is so precious in the Spring that you don't want to waste it on things that could be done earlier. With this mild autumn weather I was not in a hurry to bring them in the basement so it took about 3 weeks to make them ready for storage. In our outside shelter temperature still stays around 5°C which is perfect for tubers to stay fresh and firm.
How to divide tubers? First have a look at the tuber and find the place where new tubers are attached to the root crown that surrounds the stalk. On this tuber of
'Colorado Classic' there are 2 stalks visible with multiple tubers attached to each of them.
The stalks have to be removed. Red line shows where to cut to remove them. Yellow arrows are pointing at the visible buds at the crown of each tuber part. Each part of the divided tuber should contain a visible bud at the root crown. From this bud a whole new plant will develop and produce new root growth.
With one of the stalks removed there are more buds visible on other tuber parts. Red cross indicating the old mother tuber that has to be discarded.
Very often old mother tubers are getting rot inside of them. This rot can spread to the rest of the tuber.
Now the tuber can be cut in pieces with a sharp garden clipper.
As a result I got 12 tubers, which each will produce a plant of the same size as mother plant.
Size of tubers in dahlias depends on the variety. Some can be divided in 10-12 pieces some in 2-3 pieces only. Here is ~3/4 of my dahlia tuber harvest divided and waiting to be packed for storage. I store them in a sealed plastic bag with a bit of vermiculite or wooden shavings added to keep tubers dry. Bags are stored in Styrofoam boxes in the cool basement.
