How to Dig and Store Dahlia Tubers Without a Cooler
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As fall rolls in, it’s time for many of us to start digging up our dahlia tubers. Why? Because if they’re left in the ground in colder climates where the soil freezes, your tubers will turn to mush. If you’re in a warmer region, you might be lucky enough to leave them in the ground all year. But for those of us in areas with freezing winters, digging and storing dahlia tubers is a must.
With so much information available on how to dig and store your dahlia tubers, it can easily feel overwhelming. The reality is, there’s no single "right" way to do it because we all deal with different climates and conditions. The key is to experiment with various techniques and find what works best for you.
And anytime things feel complicated or nuanced, I like to remember the underlying goal—here, it’s to get the tubers out of the ground and keep them alive through the winter. So let’s dive into how to make that happen.
When to Dig Your Dahlia Tubers
One of the most common myths about digging up dahlia tubers is that you need to wait until after the first frost. Not true. While waiting does give tubers more time to mature, dahlia tubers can be dug around 90 to 100 days after the summer solstice. Dahlias grown in regions that don’t experience frost, such as Mexico or California, are proof that you can dig them up long before the first frost.
Personally, I prefer to dig mine in early October once our dahlia subscription has ended. Why? The sun is still shining. The temps are still in the double digits. The ground is still dry. And the plants aren’t a slimy, black goo. (It took just one cold, wet dahlia dig to learn this lesson!)
How to Dig Your Dahlia Tubers
Start by using a pitchfork (a shovel works just as well) to gently loosening the soil around the clump, taking care to dig far enough out from the tubers to avoid damaging them. When you dig too close, you risk shearing or piercing the clump with your tool. Once the tuber clump is free, remove as much soil as possible. A heavy, soil-loaded clump is harder to handle and makes storage more difficult. You can give the clump a gentle tap to loosen the dirt or pick away the soil by hand.
To Wash or Not to Wash Your Tubers?
When it comes to washing your dahlia tubers, it's entirely up to you. I've tried both ways, and here are a few things I’ve learned from my experience:
Washing Pros
If you don’t wash your tubers, you’ll bring a lot of soil (and all the little critters that live in it) into your storage area. This can get messy and isn't ideal if you’re storing them indoors.
Receiving tubers covered in another farm’s soil left me with an ick feeling. Ever since that experience, I’ve made it a habit to wash my tubers since I sell them.
Splitting your tubers is much easier when they’re washed because you can see the "eyes" more clearly.
Washing Cons
In storage, tubers with dirt left on have actually performed better for me in the past. The soil acts almost like an insulator, providing some protection.
At the end of the day, do what works best for you and your storage situation. If you decide to wash your tubers, I recommend this hose sprayer that allows you to control the water pressure making the job easier.
Drying Your Dahlia Tubers
If you’ve washed your tubers, the next step is to let them dry before putting them into storage. But here’s a word of caution—don’t let them dry out too much. I’ve had tubers shrivel in a very short period of time because I wasn’t paying close enough attention.
There’s no set drying time because it will depend on your weather conditions, but I like to keep mine in a shaded spot for 12-24 hours. Just be sure to keep an eye on them to make sure they dry enough without completely drying out!
Storing Your Dahlia Tubers: Temperature, Humidity, and Medium
When it comes to storing your dahlia tubers, there’s no one-size-fits-all solution. The method that works best for you will depend on your climate and storage space. However, there are three key factors to keep in mind: temperature, humidity, and storage medium.
Temperature:
The ideal temperature for storing dahlia tubers is between 40-45°F (4-7°C). If the temperature is too high, your tubers will begin to sprout, which you want to avoid until spring. If the temperature drops too low, the tubers will freeze and turn to mush.
While a temperature-regulated cooler is ideal for storing dahlia tubers because it allows you to control the temperature, it’s not always feasible. So, where should you store them? As I’ve mentioned before, it depends on your location. Here in Michigan, the garage isn’t an option for me because the temperatures can drop below freezing. However, if you live in a milder climate, the garage might be the perfect spot.
I once used our crawl space, and while it worked, crawling around in the sand with creepy crawlies wasn’t exactly enjoyable. The following season, I tried storing them on our basement floor. Although the basement is heated, it stays a few degrees cooler than the rest of the house, so it worked. However, the tubers started sprouting earlier than I wanted in the spring.
Now, I use a temperature-regulated cooler set to 45°F, and it has been the best solution for me. I use an Inkbird device to monitor and maintain the perfect temperature for my tubers.
I like to think of all these storage "rules" like health advice. For example, we're told to drink 8-10 glasses of water a day—it's the goal, the ideal. But will we survive if we only drink 5 glasses? Absolutely. The same goes for temperature. Aim for a storage spot around 45°F, but if you can’t hit that mark perfectly, don’t stress. Just do the best you can with the options you have. Should your temp be too warm, and your dahlias sprout too soon, simply remove the sprout! 🤷♀️
Humidity:
The ideal humidity for storing dahlia tubers is around 85%, which is quite high. If the air is too dry, the tubers may shrivel, and if the humidity is too high, you run the risk of mold or rot.
To manage this, I use a room humidifier and dehumidifier connected to an Inkbird to keep the humidity levels in check. Alternatively, you can lightly mist your tubers or the storage medium with water as needed.
Storage Medium:
Choosing the right storage medium can make a big difference in keeping your tubers healthy through the winter. You can use a medium or store them without one—this is another area where different growers have different preferences.
Here are a few options:
Vermiculite: This is my personal favorite. It’s lightweight, keeps the tubers dry, and allows for some air circulation. You can often find large bags of vermiculite at your local nursery or purchase in bulk here.
Soil: I stored my tubers with soil left on the clumps one season and if it weren’t for the mess, soil would be my medium of choice. However, it was messy, and I decided it wasn’t worth the hassle of bringing all that dirt into the storage area.
Wood shavings or Newspaper: Other popular options that are more affordable than others.
Plastic Wrap: Many gardeners swear by wrapping their tubers individually in Saran wrap to keep them protected. While I can certainly see the benefits of this method, in the past I found it too time-consuming for the number of tubers I grew. Now that I’m moving towards hobby gardening, I will definitely try this method with my high-value tubers.
Final Thoughts on Storage
Here’s something I’ve learned over time that I think is important to share: not all tubers store the same way. Some varieties could be left on the kitchen counter all winter and store beautifully, while others are, well... let’s just say they’re difficult. No matter how much care you give them, they just don’t store well. It’s nothing personal.
On the bright side, there are plenty of varieties that store beautifully with minimal effort. Some of my favorites for easy storage are Cornel, Cornel Bronze, Isabel, Caitlyn’s Joy, Wine Eyed Jill, Clearview Peachy, Jabberbox, Jowey Winnie, Just Peachy, Ivanetti, Diva and Coralie.
In the end, storing your dahlia tubers is all about finding the balance that works for you and your growing conditions. Keep experimenting until you find your groove, and your dahlias will be ready to thrive come spring!
If you’re ready to turn your passion for dahlias into a profitable venture, check out Dahlias for Profit. This guide covers everything you need to know, from growing tips to income-generating strategies, to help you make money from your dahlias.
Quick Tips
If you want to know what varieties are great tuber producers and store well? Look at dahlia tuber sales and find the varieties selling at a lower price. Those are the ones you want! Growers often have them in volume because of this!
I don’t always let me tubers dry. Sometimes, I throw them straight into the cooler.
If you use sealed plastic containers, be sure to check them from time to time. Moisture can get trapped inside the bin and cause rotting. (Learned from personal experience.)