Native to Mexico, dahlias won’t survive the freezing temperatures that many North American gardens experience. Digging and storing dahlias for the winter is extremely easy and simple if you follow these tips.
When to Dig Up Your Dahlias…
If you live in an area where the ground freezes, you’ll want to dig your dahlia tubers up before there’s a hard frost.
A good indication of when to dig your tubers up is when the plant starts to turn brown and die back.
These enormous, woody stems are left behind from first-year tubers!
What’s the Difference between a frost and a freeze?
- A frost (ice crystals forming on surfaces) generally happens when the air temperature is between 36-32 degrees F.
- A freeze happens when air temperature dips below 32 degrees F. A hard freeze is usually between 28-25 degrees F, and a killing freeze is 24 degrees F and below.
Frost Date Chart
If you live in an area where your ground doesn’t freeze – such as parts of California and Florida – lucky you, your dahlias can be grown as perennials and you don’t need to worry about digging and storing them for the winter!
5 Tips for Digging and Storing Dahlias for the Winter
1. How To Dig Tubers Up
Cut foliage back to a couple of inches from the ground, before digging your tubers up.
Digging the Dahlia tubers up is extremely easy:
- Cut foliage back, so that only a couple of inches remain above ground.
- Take your preferred digging shovel and dig around the tubers, being careful not to accidentally sever the roots. Many gardeners use a pitchfork to prevent this from happening.
- Once you’ve dug the tuber up, shake the dirt off and set it aside.
- Repeat until you’ve dug all of your tubers up.
Gently shake excess dirt off of your tubers after digging them up
2. Rinsing Dahlia Tubers Off
After you’ve dug all of the tubers up, gently wash the dirt off in a tub of water, or with a garden hose.
Make sure not to puncture the skin of your tubers, as this could cause them to rot over the winter months in storage.
3. Examining And Trimming Dahlia Tubers
After you’ve rinsed the tubers off, it’s time to examine each clump to make sure that there are no rotten parts. If there are, cut these bits off.
If the tubers have several eyes, you can divide them at this step in the process as well. Use a sharp knife to divide tubers, making sure each piece has at least one eye.
The eyes of dahlias are the set of cells that produce the next season’s plants and blooms. They almost look like pimples! If you can’t identify them in the fall, wait until the spring to divide your tubers as they may be more visible by then.
4. Drying Dahlia Tubers Before Storing For Winter
If possible, dry your dahlia tubers for several days to a week, depending on humidity, temperature, and tuber size before putting them away in storage for the winter. This helps to cure them and to prevent rot during storage.
Choose a location – either indoors or out – that won’t dip below freezing, has good air circulation, and has indirect sunlight. After your tubers have dried, cut back the rest of the dahlia stem with pruners or a sharp knife.
5. Storing Dahlia Tubers for the Winter
The key to successfully storing dahlia tubers for the winter is making sure they stay dry, have good air circulation, and are in a cool, dark spot.
You can store the tubers in a variety of containers – milk crates, plastic bins, paper bags, and cardboard boxes all do the trick. Just make sure there is space left between each tuber and there is some air circulation.
Place the tubers in a cool, dark space that won’t freeze. For many, this could be an unheated basement, attic, closet, or utility room.
Check your dahlia tubers periodically throughout the winter months. If the storage is too humid and moist, you may find mushy tubers. Remove those tubers and decrease moisture. If your tubers are becoming shriveled, mist them or add some damp vermiculite, helping them to rehydrate.
Re-Planting Dahlias In Spring
Once spring arrives, ground temperatures have warmed and there is no more chance of frost in your area, you can bring your beloved tubers out of storage and re-plant them in your garden to enjoy again and continue to enjoy the Year of the Dahlia.
“This post is provided as an educational/inspirational service of the National Garden Bureau and our members. Please credit and link to National Garden Bureau and author member when using all or parts of this article.”
how about storing them in a box filled with sawdust (lightly moistioned)?
Yes, sawdust should work. They should be stored loosely and barely moist. Monitor them during the winter so they don’t dry out. You may need to sprinkle a little water on them from time to time
Thank you for this informative article. Did not know that the bulbs should be washed, but am going to do that. I thought I would store each bulb in a section of an egg carton, that would keep them separate and my bulbs are not too big. Also thought of then placing the cartons in a big paper bag….
Margaret, if your dahlias are small enough to fit in an egg carton, you will have a difficult time overwintering them. And to place them side-by-side in the egg carton is still too close. I suggest using a grocery bag, plastic, grocery bag with vermiculite and keep it loosely tied. Paper draws moisture, so you really don’t want to put them in a paper egg carton even if they did fit, they will shrivel and dry out because the paper of the egg carton will absorb every bit of moisture that is in the dahlia..