How to Store Dahlia Tubers Over Winter: A Complete Guide
You've grown something beautiful this season. Now the question is how to save it.
Storing dahlia tubers over winter is one of the most important skills a dahlia grower can learn and one of the most misunderstood. Do it right and your tubers come back stronger every year. Do it wrong and you lose everything you grew.
Here's exactly how we do it at Rooted Dahlias, after years of learning what works and sadly, what doesn't.
When to Dig Your Tubers
Wait until after the first hard frost kills the foliage, usually when the tops turn black and die back. In most of the US this happens between October and November depending on your zone, don't dig too early! The tubers are still maturing right up until frost and you want every bit of that growing time.
If a light frost is coming but a hard freeze isn't forecast for another week or two, you can leave them in the ground a little longer. Once a killing frost hits, dig before the ground freezes solid.
How to Dig Dahlia Tubers
- Cut the stalks down to about 4–6 inches above the ground
- Use a garden fork and work it into the soil about 12 inches away from the stalk in a wide circle
- Gently lift the clump up from below rather than pulling from above. Dahlia necks break easily and a broken neck can means a lost tuber
- Lift the entire clump and shake off loose soil
- Label with the variety name. Careful, they all look the same once they're out of the ground
Curing Your Tubers
Before storing, tubers need to cure by having a drying period that toughens the skin and prevents rot in storage.
Lay your clumps upside down in a cool, dry spot out of direct sunlight. A garage, barn, or covered porch works well. This allows any remaining moisture in the stalk to drain away from the tubers and the skins to firm up.
Don't skip curing. It's generally the difference between tubers that make it through winter and ones that turn to mush by February.
Dividing Your Clumps
You can divide clumps before or after storage. If you divide in fall, make sure each division has at least one healthy eye and a piece of neck attached. Plants grow from the eye, and a tuber without an eye will never sprout.
How to Store Dahlia Tubers
The enemy of dahlia tubers in storage is moisture and freezing temperatures. Your goal is cool, dark, and slightly humid — like a root cellar.
What you need:
- A cardboard box, plastic bin, or paper bag
- Storage Medium: Peat moss, vermiculite, or slightly damp sawdust
- A cool space that stays between 35–50°F, maybe a basement, garage, or cooler
Steps:
- Place a layer of your storage medium in the bottom of your container
- Lay tubers in a single layer on top — don't let them touch each other to avoid spreading any rot or mold
- Cover with another layer of storage medium
- Store in your cool, dark space
- Check monthly — remove any tubers that show signs of rot before they spread to neighboring tubers
What to Watch For in Storage
Shriveling: If tubers look wrinkled and dry by midwinter, lightly mist your storage medium — they need just a touch more humidity.
Soft spots or mold: Remove affected tubers immediately. One rotten tuber can spread quickly through a whole box.
Freezing: If your storage space gets below 32°F, your tubers will freeze and be lost. Move them somewhere warmer. Sometimes even an interior closet is better than a freezing garage.
In Spring
Bring your tubers out of storage 2–3 weeks before planting. Let them warm up gradually in a bright spot indoors. You'll start to see tuber eyes — small white, pink or purple growth nodes will appear on the necks. Those eyes are your confirmation that the tuber is alive and ready to plant.
Want Tubers You Can Trust?
Every tuber we sell at Rooted Dahlias is hand-dug, cured, inspected, and stored with the same care described in this guide. When you order from us, you're getting a tuber that's been handled right from the moment it came out of the ground.
Our shop opens every December. Join the waitlist to be first to know when we open. 🌸
Rooted here. Blooming there.