If you want to keep your dahlias coming back year after year, you’ve got to give them a little TLC over the winter. These beauties are definitely not fans of the cold, and leaving them out in a hard frost is a surefire way to lose them. While most people swear by storing dahlia tubers in a cellar, you can actually overwinter them right in their pots! It’s a great shortcut if you’re short on storage space or don’t want to deal with digging them up.
How to Overwinter Dahlias in Pots and Planters
The gold standard for dahlia care is usually digging up the tubers and tucking them away in a cool basement. But hey, if you don’t have a root cellar or a perfect basement spot, don’t sweat it. Keeping them in their pots is a totally viable backup plan.
Step-by-Step: The Potted Method
Dahlias are actually pretty tough and can usually handle the very first light frost of the season. But once that happens, it’s time to move them into their winter home. Here’s how to do it:
- Start cutting back on the watering in September. This helps the tubers “harden off” and get ready for their long winter nap.
- Next, give your plant a major haircut. Clear away all the spent blooms and leaves. You’ll want to cut the stalks down until only about four inches (10 cm) of stem is left above the soil. The most important part? Leave the tubers right where they are—no digging required!
- Move the entire pot to a frost-free spot. You’re looking for a place that stays cool but doesn’t dip below freezing—ideally around 50°F (10°C). Since they’re staying in the dirt, they won’t dry out as fast, but you should still give them a tiny splash of water every few weeks just to keep the soil from becoming bone-dry.
- When spring rolls around, it’s time for a refresh. Take the tubers out and replant them in a new pot with fresh, nutrient-rich potting soil (or just swap out the old dirt in the current pot). If there’s still a threat of a night frost, make sure to bring the pots inside or into a garage overnight. Once the “Ice Saints” have passed in mid-May and the ground is warm, your dahlias are safe to stay outside 24/7.
Quick Cheat Sheet for Potted Overwintering
Here’s the “too long; didn’t read” version for a successful winter:
- Cut the stems down to a few inches right after the first frost.
- Leave the tubers in the pot—don’t dig them up!
- Find a frost-free storage spot (aim for 50°F max).
- Give them a light drink of water every now and then.
- Repot with fresh soil in the spring and acclimate them back to the outdoors.
