How to Dig Up and Store Dahlia Tubers Until Spring

If we had known this during our early years of growing flowers, working with dahlias would have been much easier. Here, we’re sharing the secrets of successfully storing dahlias until spring.

1. After a Hard Frost: Once a strong frost has hit and damaged the above-ground part of the plants, cut the stems back, leaving about 20 cm (8 inches) above the soil. You can also trim the top (if it’s fully frozen) right before digging them up.
Note: If only part of the foliage and flowers is frost-affected and you plan to dig up the dahlias soon, it’s better to cut the above-ground part to prevent the plant from using energy to recover shoots and tissues. This signals to the plant that the growing season has ended

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2. Wait 10–15 Days After Frost ) or after you've decided to cut them in the autumn): Before digging up the tubers, wait 10–15 days after the frost. This allows the tubers to form a protective skin, improving their storability.

3. Storage Options: If you have ample storage space, you can keep the entire tuber clump intact until spring and divide it when buds begin to sprout. In this case, there’s no need to wash the tubers; instead, shake off the soil, trim any fine roots and tubers, and soak them in a fungicide solution for about an hour, then dry them for about a week at temperatures below 10°C (50°F). Shorten the stem to 3–5 cm (1–2 inches). Drying an entire, undivided clump may take longer.
If space is limited or you don’t have time in the spring, wash the dahlias, trim the fine roots, and divide them into smaller sections now to save space.

4. Label Varieties: After washing and dividing, label each tuber according to its variety.

5. Fungicide Treatment: Treat the dahlia divisions in a fungicide solution, and dust the cut ends with ash. Dry them, spreading out and turning the tubers evenly for 4–7 days at about 10°C (50°F).

6. Optimal Storage Method: There are many ways to store dahlias until spring, and we have tried most of them. For the most reliable method, store in plastic crates with vermiculite in a space (basement, garage, or cellar) with a stable temperature no higher than 6°C (43°F) and consistent humidity. Vermiculite is highly absorbent, helping to balance moisture levels and acting as a mild antiseptic. Sand and peat moss don’t absorb moisture as well and can contain nutrients that promote pathogens if moisture gets in.

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Although fall might feel like the time to rest, prepping dahlias for storage is a vital and careful task. Put in the effort now to do it well, as the quality of your planting material next season will depend on it.


Wishing you success with these essential tasks, and we’d be happy to answer any questions!

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