The Ultimate Guide to Storing Dahlia Tubers Over Winter
It’s that time of the year again! As many of you know, dahlias are only perennials in their native home of Central America. Because our farm sits in Zones 3 and 4, we have to dig up our tubers every autumn to protect them from the frost. Follow along with our step-by-step guide below—we’ve included plenty of photos to make the process as easy as possible. Happy digging!
Step 1: Dig Wide to Protect the Tubers
First, grab a spade or shovel! Make sure to start digging about 12 inches away from the main stem on all sides. Dahlias spread their roots wide underground, and keeping your distance ensures you won't accidentally puncture or slice into any precious tubers.
Here is a look at what a freshly lifted dahlia clump looks like! Depending on your soil type, you might find a heavy ball of earth clinging to the clump, or the soil may fall away quite easily. Clay soils tend to hold on tight, while sandy soils usually drop right off.
Step 2: Clear the Soil Safely
Next, it’s time to knock off that excess soil! Hold the tuber clump by the main stem and gently drop it stem-first onto the ground. This quick impact helps shake the dirt free. Important: Never throw or drop the clump tuber-side down, as the impact can easily snap or crush your delicate tubers!
Identifying Dahlia Eyes
Looking closely at your cleaned clump, can you spot the eyes?
What are dahlia eyes?
Dahlia eyes are small growth nodes found right at the collar of the tuber, where it attaches to the main central stalk. They often look like tiny green or purple/pink swollen buds, similar to potato eyes.
Look at our pile of dahlia tubers!
Step 3: Hose Down the Tubers
Note: This step is optional for home gardeners, but essential for flower farms.
We wash all of our tuber clumps thoroughly before storing and shipping. For us, it’s about quality and safety—we want to deliver clean tubers to our customers without exporting our local soil. For home growers, washing is still a great practice because unwashed soil can harbor hidden pests or fungal spores that lead to rot during winter storage.
A nicely washed tuber clump.
Step 4: Air-Drying (24 Hours)
Once washed, place your tubers in a well-ventilated area for 24 hours to dry. We place our tubers on open wire shelves or inside ventilated, heavy-duty plastic crates to ensure maximum airflow from all sides.
Why you should avoid concrete:
Avoid setting tubers directly on concrete garage or basement floors. Concrete is naturally porous and high in alkalinity, creating a strong capillary action that draws moisture out of anything resting on its surface. Placing tubers on bare concrete wicks away their essential internal water, leading to shriveled, unviable tubers.
Now that your tuber clump is prepped and ready, it's time to get down to dividing your dahlias!
Before you start cutting, grab your tools:
Heavy-duty snips: Make sure they are nice and sharp.
Sanitizing jar: A mixture of 10% bleach and 90% water to clean your blades between cuts.
Hand protection: I highly recommend wearing gloves. Because we divide thousands of tubers each year, I personally wear chainmail gloves—one quick slip with a sharp blade can easily put you out of commission for the season!
Now we’re ready to divide. Before you begin cutting, check out this quick video demonstration:
🎬 Video Guide: How to Divide Dahlia Tubers Step-by-Step
Step 1: Start by identifying an outer tuber that is easy to reach and clearly exposed, like the one shown here. Remember, for a tuber to be viable it requires an eye, neck and body.
Make a clean cut through the stem base, taking extra care not to nick or damage the eyes or the neck of the tuber.
If an eye isn't easily visible on the upper side, flip the clump over. Working from the underside can give you a much clearer view of the eyes and crown.
Continue rotating the clump and separating individual tubers until you've worked through the entire root system. You'll end up with a generous batch of viable tubers, ready for next season!
Notice this larger, darker tuber with the tougher skin? That’s the original 'mama tuber' planted earlier in the season. Unless your harvest was light and you need every tuber you can get, it's best to toss these out—they've done their job and aren't ideal for replanting.
Next up: trimming and cleaning up each individual tuber. You'll want to trim off any thin feeder roots, as well as any extra tubers that don't have eyes. Feeder roots can harbor fungi and rot during winter storage, while eyeless tubers are non-viable—keeping them just wastes valuable storage space!
Cleaned up tuber.
Now that we have our pile all cleaned up, look at how many tubers we got! The variety we used here is called 'Who Dun It,' which produces some of the biggest clumps in our entire collection—19 tubers!
With your tubers prepped, it's time to pack them away for winter storage!
The Goal: Keep them in a dark space so they stay fully dormant. The environment needs to strike a goldilocks balance—not bone-dry, but definitely not wet.
The Storage Medium: We’ve tried peat moss, wood shavings, and coarse vermiculite. Hands down, vermiculite gives us the best results, keeping nearly 100% of our tubers healthy through spring.
The Containers: Storing thousands of tubers requires an efficient system. We use plastic shoe-box containers with ventilation holes cut into the top. This allows excess condensation or residual moisture to evaporate instead of causing rot.
We cover them with vermiculite
Mark them and store them away for storage
Coffee containers are another excellent budget-friendly option. Simply poke several drainage holes in the bottom using a screwdriver, and move them to your home’s coolest closet.
On a side note, we are currently testing storing these tubers through a second dormant season. If successful, this two-year storage method will serve as a safety net in case of crop failure.
Et voilà! You’re all set—just leave them undisturbed until spring.
A little 2026 photo dump ❤️
