Jack Frost is in the air, so it is time to start thinking about what to do with your dahlia tubers. Are you prepared for this process? You have three choices:
Leave them in the ground and let the freeze kill them, or dig them up and discard the tubers so you do not have to store them through the winter.
Leave the tubers in the ground and provide adequate coverage/insulation to ensure they last through the winter.
Dig them up and store them so you do not have to worry about the cold weather killing your tubers.
Option 1 is self-explanatory. Let's discuss options 2 and 3:
Option 2: It might be a good idea to create a map identifying the name of each tuber so you know what you have in the ground in case you want to add any additional tubers the following year. You may want to dig them up in the spring to divide your tubers (we will discuss this later). This way, you will have multiple plants of the same variety, or you can share them with your neighbor.
What do you need to do? The first hard frost should kill your plants (they will turn black). Then, wait about two weeks unless the weather forecast in your area predicts extremely cold weather. If you do not have a hard frost, then by the middle of November, you will need to do the following:
With loppers, cut off the main stalk. Then carefully dig around the stalk without digging down to the tubers.
Make additional cuts of the stalk until the hollow portion of the stalk can no longer be seen.
Place a piece of tarp over the plant. This will prevent any moisture from penetrating the soil down to your tubers. Moisture may cause the tuber to rot or freeze.
Next, place about 3-4 inches of dirt, compost, or other material to provide insulation from the cold.
Option 3: Dig up your tubers and place them in storage. Similar to option 2, wait about two weeks after the first hard frost unless the forecast in your area predicts extremely cold weather; then, it can be done sooner. If you do not have a hard frost, by the middle of November, you will need to do the following:
With loppers, cut the main stalk down to ground level.
With a garden fork, start about 1 foot from the stalk and dig around the dahlia.
Carefully dig it out to avoid breaking off any tubers.
Knock off as much dirt as possible without harming the tubers.
Wash off the remaining dirt.
Allow the tubers to dry for about 24 hours.
Once dry, write the tuber's name with an Indelible Ink Pencil.
I will try to provide a video showing how to do options 2 and 3. We will discuss how to store the tubers a little later.