Dahlias are one of the most rewarding flowers to grow, but if you live in a colder climate, it’s important to dig and store your tubers for the winter. Most dahlia tubers cannot survive freezing temperatures in USDA Zone 8 or below, so proper storage ensures your plants will come back year after year.

Here’s how to prepare your dahlias for digging and safe winter storage.

Step 1: Label Your Plants

Before frost hits, make sure your dahlias are labeled. Once a hard frost arrives, the entire plant, including the blooms, will turn black, making it nearly impossible to identify varieties.

Labeling while the plant is still alive ensures you’ll know which tubers belong to which bloom when spring planting time comes around.

Step 2: Wait for a Killing Frost

Dahlias are typically dug in October or early November after a killing frost. This frost will blacken the foliage and signal that the plant is ready to be cut back.

Once frost arrives, wait 5–10 days before cutting down your plants. This short wait allows the tubers to form a slightly thicker skin, which helps them store better through the winter.

Step 3: Cut Back the Foliage

Use whatever tool works best for you, (big tree loppers, heavy-duty hand pruners, or even a hedge trimmer) to cut down the tall dahlia stalks.

Be sure to remove any staking or twine before you begin. Then cut the stalks down leaving 8-12" to grab onto.

Watch this short video on cutting back foliage. 

Step 4: Begin Digging

You can start digging tubers right away after cutting the stalks back. Once the clumps are out of the ground, it’s helpful to divide them in half (at minimum).

Why divide? The center of the clump often holds moisture, and if left intact, it’s usually the first area to rot during storage. Cutting it open helps the tubers dry more thoroughly and prevents rot.

Watch this short video on digging dahlia tubers. 

Step 5: Cure and Store

After digging and dividing, let your tubers sit out for 24–48 hours to dry. This short curing period allows excess moisture to evaporate.

Next, pack them away in a container filled with peat moss or pine shavings. Store them in a location that stays dry and does not freeze, such as a garage, basement, or shed.

Can You Leave Tubers in the Ground?

In some cases, yes. If you live in a milder climate and want to try overwintering your tubers in the soil, you’ll need to cover them with a thick layer of mulch or straw, then add a protective layer of landscape fabric or plastic to keep them dry.

The key is that tubers must not freeze and must stay relatively dry. For most growers, digging and storing indoors is the safest option.