Dahlias are already a complex perennial to grow, and they can become even more challenging to grow during the wintertime.
Thoughts and queries like when to dig them, how to store them, and where to replant them confuse the heck out of new gardeners, and they start to move away from this beautiful perennial for this exact reason.
In this article, I’ll make the process of overwintering dahlias simple for you. Every question you can possibly imagine will be answered today, so just keep reading!
Should You Dig Or Leave Dahlias In The Ground?
Whether you should dig out your dahlias or leave them in the ground during the wintertime will mainly depend on the USDA zone you’re in.
Being aware of different zones and knowing which zone you’re working in can prove to be a very meaningful advantage when growing perennials as sensitive as dahlias.
Also take a look at why your dahlias might not bloom if you’ve struggled with flower production in past seasons.
When Is The Best Time To Divide & Dig Dahlia Tubers?
Generally speaking, you want to wait until after the first hard frost to dig and divide dahlia tubers. This would be around the time when the foliage starts to fade and die back, helping the tubers toughen up on their own.
After 1-2 whole weeks, you can cure the tubers in the ground before digging. For the safest and best possible results, doing this 10-12 days after the first hard frost is ideal.
If there’s no frost in your area, digging in mid-November is your best bet. This timing will ensure the tubers are protected from frost damage as much as possible.
While some people like to divide their dahlias in the spring, I always divide my dahlias in the fall right after digging them up. The eyes are still visible on the crown, and it saves me from having to store bulky clumps all winter. Also, I find it easier to deal with smaller divisions when packing them away for storage.
If you’re not sure what to do once flowers fade, here’s a simple guide on how and when to deadhead dahlias!
Easy Step-By-Step On How To Dig, Divide, Cure, & Store Dahlia Tubers
Step 1: Tag Your Plants
Though this may sound a little odd, try tagging your plants before frost, as it helps with memory and will allow you to recognize tubers after their foliage dies.
Step 2: Cut Back Foliage
Once frost has passed, cut back the foliage ever so slightly. Leave 3-6 inch stems behind and try not to overdo this prune. Waiting 1-2 weeks after this step to let the tubers cure isn’t necessary, but highly recommended.
Step 3: Dig Up the Clump
Using a small garden fork or shovel, dig gently 10-12 inches around the dahlias to be able to lift the whole clump while keeping it intact.
Step 4: Clean Off the Soil
Shake off excess dirt and debris gently. DO NOT wash it unless the soil is hard and compacted (which I sometimes need to do).
Step 5: Divide the Tubers
With clean pruners or a knife, carefully divide the clump into smaller sections. Make sure each tuber has at least one “eye” attached to the crown, since that’s where next year’s growth will sprout.
Dividing now saves storage space and prevents rot from spreading through a whole clump.
Note: Some gardeners prefer to wait until spring to divide, which can make it easier to spot the eye once the tubers start waking up (especially if you’re a beginner). If you’re taking that route, just store the whole clump as-is and divide when you see the new growth points.
Step 6: Label & Protect
Before storing, dust the cut tips with cinnamon to prevent mold. Then, write on each tuber (like “O. Sylvia”) so you know exactly which variety you’re replanting in spring. A little organization now saves big confusion later!
Step 7: Pack for Storage
Pack the divided tubers into a breathable plastic bag filled with lightly moistened wood shavings (you can also use peat or vermiculite). This keeps them cushioned and helps maintain the right amount of moisture without letting them dry out.
Step 8: Storing
Store the packed and labeled tubers in a well-ventilated container at 36-50°F (or 2-10°C). Check them from time to time. Mist lightly if they look shriveled, and remove any that show signs of rot!
Now, You Must Replant In Spring!
After the last frost goes by and warmth begins to set in, that is the time you want to be bringing tubers out into the light and planning to replant them.
Since I’ve already divided mine in fall, all that’s left to do in spring is replant them in raised beds or borders, spacing them properly and staking as needed.
If you chose not to divide in fall, this is the stage where you can split the clumps before planting. By now, the eyes are usually visible, making it easier to see where to cut.
Either way, once they’re in the ground with good spacing and support, your dahlias are set up for another season of big, beautiful blooms!
For another perennial with similar questions, see whether to cut back or leave peonies after flowering!
Let’s Conclude
Overwintering dahlias can be one hell of a job, considering how sensitive they are to temperature changes and the amount of love and attention they constantly require to get through tough periods. However, if you’re actually passionate about them, it will surely feel like energy well spent!
This is my first year growing and I did it from seed. There are 2 plants that have put out about 2’ x 3’ area of flowers. They kind of look like yellow daisy’s. They are all yellow. They have about 2” circumference.
When I dig them up in a week or 2
i should have tubulars that I’ll separate . Can you tell me when I plant them next year how many tubulars should I plant together. For a full look.
Hi Cyndy! 😊 That sounds like dahlias! When you replant next spring, I usually put one healthy tuber (or a clump with one “eye”) per spot. Space them about 18 inches apart, they’ll fill in fast once they start growing.