As the gardening season winds down and the first hard frosts darken the dahlia foliage, the real work begins. Dahlias won’t survive a mid-Atlantic winter in the ground, but with just a bit of care they can be saved, multiplied, and brought back into bloom next summer even stronger than before.
I always think of this task as a quiet fall ritual — a way of closing the garden year and making a promise to the next one. Lifting and storing tubers might seem intimidating at first, but once you understand the steps, it is simple, satisfying, and even rewarding. Many gardeners are surprised at how easy it is to increase their collection; one tuber can become five or six for next season.
The key is timing, careful handling, and proper storage. Moisture and temperature make all the difference between success and rot. With a few simple techniques — labeling, drying, storing correctly, and checking them over winter — dahlias overwinter beautifully and reward you with months of bloom.
Below is my tried-and-true method: clear, step-by-step, and tested over many years in my garden. Feel free to print it, pin it, or keep it by your potting bench.
1. Timing: When to Dig
Wait for the first hard frost to blacken the foliage. This signals the tubers to enter dormancy.
Signs it’s time:
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Leaves and stems turn dark and limp.
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Temperatures consistently dip below 32°F.
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Growth has clearly stopped.
You can dig before frost if a deep freeze is predicted—but always label the plant while it’s still in bloom, or you’ll forget which is which.
2. Cutting Back & Lifting the Tubers
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Cut stems down to about 4 inches above soil level.
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Using a garden fork (not a shovel—less damage!), gently loosen soil in a wide circle around the plant.
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Lift the clump carefully—dahlia necks snap easily.
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Shake off excess soil – it isn’t necessary to rinse them. I skip this as I have so many!
3. Drying
Drying is critical—wet tubers will rot in storage.
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Place tubers upside-down in trays or crates. I store these on the floor of my greenhouse that stays above freezing. An unheated garage would work also.
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Let them dry for at least 24–48 hours in a cool, airy place.
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Turn occasionally to prevent moisture pockets.
4. Labeling: Don’t Skip This!
Use waterproof garden tags or write directly on the tuber with a Sharpie oil-based paint pen.
Label before drying, while you still know what’s what.
5. Optional: Dividing Before Storage
You can divide now or wait until spring. I like to do it in the fall when I have more time.
If you divide now:
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Each division must have an “eye” (the growth point near the stem).
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Use a clean, sharp knife or hori-hori tool.
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Dust cut edges with sulfur powder or cinnamon – both act as natural fungicides.
6. Methods of Storage
Dahlias need:
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Darkness
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Good airflow
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Temperatures between 40–50°F
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Slight humidity (not bone dry)
Best storage mediums:
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Peat moss
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Sawdust
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Wood shavings or pet bedding
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Vermiculite
Lay tubers in a single layer or nest them loosely—not packed tight. Store in:
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Cardboard boxes
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Plastic crates with ventilation
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Paper bags for small varieties
Avoid sealed plastic containers — they trap moisture and cause rot.
7. Winter Checkups
Once a month, open your boxes and inspect:
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If tubers shrivel → lightly mist the storage medium.
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If tubers soften or smell musty → remove immediately to prevent spread.
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Fungus? → dust with cinnamon or sulfur powder.
8. Waking Them Up in Spring
As the days get longer and warm up, my dahlias will start to sprout with long white shoots as they are kept in the dark. I start to pot up my tubers in potting soil in gallon containers to get a head start in the spring.
Once soil warms to 55°F, they’re safe to plant outside. See my post on planting out.
9. Bonus Tip: Expanding Your Dahlia Collection
Your winter storage ritual is also the perfect time to:
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Divide and multiply your collection
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Trade varieties with fellow gardeners
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Start a tuber inventory for next year’s cutting garden
Final Thought
Digging and storing dahlias is a fall ritual that connects one growing season to the next. It’s a gesture of faith—tucking beauty away for safekeeping—knowing it will return even stronger in spring.
