Digging up your plants in the fall isn’t always an enjoyable task. In areas with cold winters, though, you must get them out of the ground if you want them to survive. Once they are dug up, it’s also essential they are stored correctly through the winter to keep them from rotting or drying out completely.
So let’s talk about different ways to properly store dahlia tubers for the winter, including an easy (albeit somewhat contested) method.
Who Should Dig Up Dahlias For The Winter?
As dahlias are classified as “tender perennials,” you must dig them up if you live in a hardiness zone that experiences cold winter temperatures. Even in zones 8 and higher, you’d benefit from lifting them to minimize rot. Digging them up and storing them indoors for the winter allows you to replant them the following spring for another year of enjoyment.
Prepping Dahlia Tubers For Storage
After you carefully dig your tubers up, you need to prepare them for winter storage to minimize problems. Cleaning and drying the tubers before packing them away cuts down on mold and rot considerably, showing how a few minutes of prevention is critical and much easier than addressing problems after the fact.
- Start by cutting all of the stems off a couple of inches above the dahlia’s swollen, fleshy tuber.
- Use your fingers to brush as much soil from around the tubers and roots without damaging or breaking them.
- Wash the remaining soil off using a gentle spray from your garden hose.
- (Optional) Divide or separate large clumps into smaller ones for planting next spring.
- Lastly, set the newly cleaned tubers in the sun to cure for a few days or weeks.
Traditional Winter Storage Methods
A quick online search gives you a handful of different options for storing your dahlia tubers. In many cases, each gardener tells you their method is the best. Truthfully, the best approach is what works well for you. So, here are a couple of the most popular storage methods for you to experiment with, determining which is best.
The goal with storage is to keep the tubers from drying out entirely yet not rotting because they are too moist.
The Paper Bag Storage Method
One of the easiest methods for storage is putting the tubers in brown paper bags with some packing material to keep the roots from breaking off. This method is quite similar to how tubers are packaged for sale and works well in milder climates. Put tuber clumps into a paper bag with peat moss, sawdust, or newspaper shreds.
You can then pack multiple bags into a container for storage or toss the individual bags on a shelf somewhere for the winter.
Packing Tubers in Bins Or Boxes
The most common winter storage method is packing the tubers in boxes or bins to protect them until spring. This method is handy in areas with harsh winters. Separating them minimizes damage since they aren’t jostled around and keeps disease from spreading if one is infected or begins rotting.
- Select a sturdy storage container big enough to hold your tubers and layers of packing material. Many people use plastic storage bins or Styrofoam ice chests.
- Spread a two-inch layer of peat moss, wood shavings, sand, or perlite on the bottom of the storage bin.
- Carefully place the tubers on top of this layer, leaving a couple of inches of space between each one.
- Cover the tubers with another two inches of material.
- Repeat the process as necessary, finishing with a layer of packing material on top.
Plastic Wrap Method
Some gardeners take the extra step and wrap each individual tuber entirely in plastic wrap before packing them for the winter. Wrapping them helps hold moisture, so the fleshy part doesn’t dry out too much in storage. After wrapping your tubers, you can put them in boxes or bags (with packing material) until spring.
An Easy, Alternative Way To Dig Up And Store Dahlia Tubers
Yep, I get it. Digging tubers up, cleaning them, and securely packing them away is time-consuming. Especially when your fall to-do list is long as you’re trying to get the yard and garden ready for winter. Some places online recommend this easy storage method and claim it works well.
The key to this “dirty” storage is not cleaning all of the soil off after digging them and then misting them a couple of times through the winter to keep them moist.
The “Dirty Dry Storage” Method
- First, cut the dahlia stems off five to six inches above the ground.
- Carefully dig the dahlias out of the ground using a gardening fork.
- Pick the plants up using the stems as a handle and shake as much soil off as possible.
- Then use your fingers to remove as much soil as you can from between the tubers. But don’t clean all of the soil off of the tubers. This acts as insulation through the winter.
- Set the whole cluster in a plastic milk crate or cardboard box and put them in storage.
- Two or three times over the winter, mist the clumps to dampen the tubers, keeping them from drying up.
Optimal Winter Storage Conditions
The storage conditions you keep your tubers in are as important as the method you use. The goal is to keep the tubers at a temperature slightly above freezing but cool enough they stay dormant. With that in mind, the optimal storage temperature is between 40 and 50°F. You also want the area to be dimly lit or dark.
Many people store their tubers in their garage or basement, but you could keep them in an attic or an unheated sunroom as long as the temperatures are ideal.
Signs Your Tubers Didn’t Survive Winter Storage
Sometimes, you’ll have tubers that don’t make it through the winter even with the best efforts. They will dry out somewhat during the winter, looking slightly shriveled and sad come spring. It isn’t uncommon for gardeners to pull them out and question if they lived. If your tubers show the following problems, they might not be viable.
- Visible mold covers the outside of the tuber.
- Soft, squishy, rotted spots that give way with firm pressure.
The challenging part, though, is if you see these problems, it’s hard to know if it is entirely dead. If there is a tiny spot of moist flesh inside, they may still send up new shoots after planting. But if the rot is severe, there isn’t a high likelihood that it is alive.