How to Save Dahlias for Another Year!

This post may contain affiliate links, for more information, see my disclosures here.

Dahlias are an increasingly popular cut flower to grow- grown by both beginning gardeners + seasoned flower farmers alike…

And for good reason!

Dahlias are beautiful, prolific and relatively easy-to-grow.

But believe it or not, none of these reasons were motivations that led me to start growing dahlias myself.

You see, back in 2019, I planted my very first cutting garden. I was eager to fill it with flowers of all shapes, colors + varieties. In my early days, I didn’t care so much about what I grew (after all, everything looked beautiful to me); I just knew that I wanted to grow A LOT of flowers.

I dreamed of cultivating long, lush rows of beautiful flowers that I could admire as I wandered through my garden space.

Like many of you, I’m sure- my wish list for what I wanted in my flower garden was LARGE- but my budget was NOT.

During my first year of growing flowers, I grew strictly for hobby. I had no intention of monetizing my garden into a business. And so, I couldn’t fathom spending so much money on seeds of annual flowers that were just going to die back at the season’s end.

It didn’t matter how much joy I believed that my cutting garden was going to bring me- my Type A, analytical mind wouldn’t allow myself to entertain the idea of growing a seemingly low-utility product like flowers- especially while my finances were so tight.

Related: The Reason I Now Grow Cut Flowers

When I heard, however, that dahlias were sort of the exception to the rule- my interest was piqued.

Now, years later, I can confirm to all of you who find themselves in a similar boat as mine- it’s true, you can continue to have dahlia tubers for many years to come if you learn to care for them properly.

The magic of dahlias is that while they do require a higher initial investment (dahlias can cost anywhere from $6 to $20 and beyond for a single tuber) compared to annuals (which may cost $5 to $9 for a packet of 100 seeds)- a single dahlia tuber planted in the spring will multiple into a more abundant clump by the season’s end. That clump can then be separated and divided into individual tubers which will again multiple if planted in your garden the following spring.

As you can see, with a little time + effort (and a healthy amount of patience), your initial investment of dahlias will reward you with blooms for years to come. It’s truly the gift that keeps on giving!

Now if all of this sounds too good to be true or you’re confused by how this process even works, don’t worry- I’m here to help you gain a bit of clarity.

In this blog post, I’m sharing everything you need to know about storing and dividing dahlia tubers so you’ll be able to enjoy these blooms season after season.

How To Save Dahlia Tubers For Another Year

The process for saving dahlia tubers so that you can grow them in your garden year after year varies largely depending on who you talk to.

There’s honestly no one-size-fits all solution when it comes to dahlia storing and dividing.

Now the good thing about this is that it means you have more options. And you absolutely can utilize a process that feels more tailored-made for you.

The downside though is that it may take more trial-and-error on your part to really find what works for you.

The reality is that factors such as your region’s climate, the resources you have available to you, and even your personal goals for your cutting garden- they can all affect how you choose to overwinter your dahlias.

So the first question you should be asking yourself is… do you have to dig your dahlia tubers every year?

Here in West Michigan where I live, it’s simply too cold to keep my tubers in the ground all winter long. And so each fall, after my plants have stopped producing and have been taken out by our first hard frost, I begin the process of lifting my tuber clumps from the ground.

Dahlia tubers are thin-skinned and can only handle short bouts of cool temps. Generally it’s advised that growers in USDA hardiness zones 7 and below dig their tubers in the fall and store them indoors, safe from prolonged exposure to freezing temperatures.

Now once your tubers are dug, you can choose to either: store your dahlia tubers as entire clumps (and divide in early spring) or you can divide right away and store the divided tubers individually.

Neither one way is better than the other, it more depends on the time (and space) you have available.
Personally, I prefer to store my dahlia clumps whole as I’m often busy in the fall tending to our fall farm stand + preparing for our winter market. I just don’t have the extra time to devote to dividing dahlia tubers as well.

Now, in a moment I’ll share more details on how to store dahlias so that you can better gauge which of the two practices that I just mentioned make more sense for you- but before we get there let’s discuss how to divide your dahlia tubers.

How To Divide Your Dahlia Tubers:

If you’re new to growing dahlias, the question you’re most likely wondering is: do you even have to divide your dahlia clumps? Or can you just plant out the entire clump next year?

You can certainly leave your dahlia clump as a single unit and plant it out the following year. Understand that your tuber clump will naturally have more ‘eyes’ which new growth will emerge from. In some cases (when tuber clumps are especially large), too many shoots coming off the same clump can result in overcrowded plants that amass a tangle of foliage- ultimately making your them more prone to disease like powdery mildew.

In my opinion, it’s good practice to divide your tubers at least once every couple of years to ensure the health of your plants.

How exactly do you divide your tubers?

Dahlia tubers are all unique in that they come in a variety of shapes + sizes. A tuber doesn’t have to look any one way. What’s most important is that for your tuber to be viable- for it to produce flowers next season- it needs to have the following 3 things:

1. A body to the tuber which supplies the tuber with enough stored energy to get the growing process started next spring.
2. An eye on the crown of the tuber which is where new growth will form.
3. And a strong sturdy neck that connects the crown to the body.

So to take our tuber clump and break it down into individual tubers, the first thing I like to do is to make my clump easier to work with which means my first priority is removing any tubers that have broken necks.

I know for a fact that these tubers will not be viable next year.

You see, since the connection between the crown and tuber is broken, the tuber is unable to send energy to the crown of the plant and signal new growth to emerge.

Next, I find it easier to break my clump down into more manageable chunks. Depending on how large my tuber clump is I may divide it in half or even fourths.

This step can feel intimidating. You may find it difficult to identify a clean cut where you’re not cutting into (and sacrificing) a perfectly healthy tuber.

I used to feel especially frustrated because I’d watch tutorials from other flower farmers on YouTube and I couldn’t understand how they made the process so simple + straightforward.

Trust me, it’s normal to wreck a few tubers in the dividing process. My encouragement to you is that you approach dahlia dividing, not with the intention of getting every single tuber you can, but instead remember that getting even just one additional tuber from your efforts is still more than you started with.

Once my clump is divided into manageable chunks, my next step is to identify those three essential components of the dahlia tuber that we just mentioned (eye, body + neck).

Using sharp snips, I slice through the crown of the clump (making sure that at least 1 cm2 of crown remains in tack with the tuber) and I separate it out.

Repeat this process until you’ve fully separated each tuber from the clump.

And viola, from one tuber that was planted last season, you’ve now successfully transformed it into many- all which will produce an abundance of blooms for you to enjoy all over again!

Now let’s talk storage…

How To Store Dahlia Tubers:

When it comes to storing your dahlias, the most notable difference between storing clumps versus individual tubers is the space required.

Clumps are a bit more bulky to handle and simply require more space during the storage process.

If space is a limiting factor for you, dividing your clumps in the fall and storing them over the winter as individual tubers may make more sense for you.

Regardless of whether you go the individual tuber or clump route, dahlias require the same set of unique conditions for storage. That is, they ideally should be kept in a cool environment that maintains temperatures between 40 and 50 degrees Fahrenheit. It’s important that you protect your tubers from freezing temperatures as dahlias are extremely sensitive to cold and will often perish if allowed to freeze.

In addition to temperature, it’s also important that your storage space maintains a relatively high humidity. Most dahlia resources will encourage you to try + maintain a relative humidity of 75 to 85 percent.

If your humidity is too low, you may find that your tubers shrivel + dry up. Conversely, if your humidity is too high, you run the risk of your tubers developing mold and/or rotting in storage.

The proper moisture level in your storage space helps your tubers stay plump and healthy through the winter.

It’s taken me a number of years to nail down the right method + location to store my tubers properly over the winter, but I’ve found what works best for me is storing my tuber clumps in bulb crates (with some dirt left on them) which I then store in my unheated garage. Luckily for me, my garage space naturally maintains an average temperature of 42 degrees (I keep a temperature monitor in there to be sure).

If I’m dividing my tubers first + then storing, I prefer to use a bit of peat moss to help regulate the moisture of my tubers.

What I do is, I line my bulb crate with a clear plastic recycling bag, I add a thin layer of peat moss to the bottom and then place a single layer of tubers on top. I’ll then add more peat moss to cover those tubers and I’ll repeat this process, creating layers of tubers much the same way you’d construct a lasagna. Once I reach the top of the crate, I fold the bag over and poke a few holes in the top to help maintain air flow.

If you’re storing tubers in smaller quantities and you don’t need to use large crates you can mimic this same process by using small Sterilite Containers instead.

Now, if you’re unsure of whether or not a storage method will work for you, I encourage you to go with your instincts + just try something out. Then, every few weeks, be sure to check on your tubers to see how they’re holding up.

If you find that your tubers look shriveled + dehydrated, try adding more moisture into your space either by moving your tubers to a new location or using a medium like peat moss or vermiculite that can hold a bit of water. Likewise, if your tubers look like they’re on the verge of turning to mush, your space may be too moist and you either need to move them somewhere that’s dryer or you can try using a medium like wood shavings with your tubers that will help draw out excess moisture.

As we close out this blog post, I do want to leave you with one final reminder, no method of storing and dividing dahlias is ever fool-proof. Despite our best efforts, we have plenty of years here at Two Sisters Flower Farm where we experience loss- whether it be from an error on our part or just the luck of the draw.

My encouragement to you is not to be discouraged when this happens. Understand that gardening + working with Mother Nature comes with its own set of unique challenges. I promise though, if you push through and just keep trying, eventually you’ll be rewarded for your hard work.

Answers to Common Questions about Storing and Dividing Dahlias:

What’s the best method for digging up dahlia tubers without damaging them?
Use a pitchfork to gently lift your tubers, starting a few inches away from the base to avoid damaging them.

Do I need to wash my dahlia clumps after digging or before storing?
While you certainly can give your tubers a good rinse after digging (cleaning them can help to remove excess soil, making them, in some cases, easier to divide)- know that washing is not a necessary step.

Where should I store dahlia tubers to keep them from rotting or drying out?
Store them in a cool, dark place like a basement, shed/barn, or unheated garage.

What should I do if my stored tubers start to shrivel or dry out?
Lightly mist them or place them in slightly damp peat moss to rehydrate.

Do divided tubers need a certain number of eyes to grow?
Each tuber must have at least one eye to grow into a new plant.

How do I check for viability before replanting the tubers?
Look for firm tubers with visible eyes or sprouts. Discard any that are soft or mushy.

Let me know, in the comments below, what other questions you have regarding dahlia tubers! Or better yet, share your experience in saving dahlia tubers so we can learn what works best for you!