Will Dahlias Overwinter in Zone 7, Tennessee? Clay Soil? 

Spring dahlia that overwintered in the ground during our Tennessee winter!

    Last year, I dug a few sets of tubers because I was afraid that they would succumb to the bitter, wet Tennessee winter in this heavy clay.

    I only dug a few dahlia clumps, and I ended up having to discard one of those clumps of tubers. Not something I was really happy about, but it needed to be done. 

    The rest? I decided to leave them to ride out the frigid winter months and see what would come of them this spring. They weren't my favorite dahlias, so I wasn't too concerned about losing them. 

    In short, I'm really glad I did it, because I learned a few other things in the process! 

Will Dahlias Overwinter in Zone 7?

 Did My Dahlia Tubers Survive the Zone 7 Winter? 

    Sometime during April, after a long wait, the remaining dahlia clumps (the ones I didn't dig) sprung to life with enthusiasm. 

    They not only roared to life, but they sure looked like they'd just enjoyed the best nap of their lives.

    

    They were vibrantly green, lush, and growing rapidly. 

    They looked far better than the tubers that I was waking up (from my fall order.) 

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These are tubers I ordered back in fall, and have since planted out. Hopefully, I get some beautiful dahlia flowers from this order!

An overwintered dahlia, blooming profusely by early June!

Why I Was Afraid of Leaving Dahlias in Ground During a Tennessee Winter?

    From what I've read, dahlias should be dug and stored during winter, even in zone 7. They're not supposed to be able to handle the winter here, so I was worried I'd lose them.

    In addition to the cold weather, we have clay soil and wet winters. This means that the ground is very wet and waterlogged for long periods during fall, winter, and early spring.

 

Clay Soil and Dahlia Tubers: Risking Rot During Winter

    They'd not only have to deal with the cold weather; they'd have to deal with conditions that are perfect for rot to occur, as well. 

    Clay soil is excellent for holding onto moisture, but that's the last thing that dahlia tubers need. Those conditions can promote rot and fungal infections. 

    Dahlias enjoy well-draining soil, and that's especially important during dormancy. 

    However, it looks like my tubers beat the odds! 

Dahlia blooming after staying in the ground all winter in Tennessee.

Will I Overwinter Dahlias Again in The Ground in Tennessee? 

    Will I overwinter these beautiful flowers in-ground again here in Tennessee? 

    Absolutely! 

    I was very happy with the results, and while there were only a few in ground, they came back and are happier than ever. 

    I'm willing to risk this year's tubers to see what happens next spring, as I noticed a few other benefits besides the saved labor.

    They might just make it onto my list of crops that grow themselves if they continue to make overwintering easy for me!

There's nothing quite like beautiful dahlia flowers in early June, before the rough, humid Tennessee summer heat hits. (okay, it's already rough, but it ain't the worst yet!)

The Benefits to Leaving My Dahlia Tubers in the Ground Over Winter

    Firstly, digging dahlia tubers and storing them is a lot of labor in and of itself. By leaving them in ground, this is one less chore I had to do in fall. 

    Next, tubers in storage run the risk of rotting, too. They also run the risk of shriveling up and dying; tubers can be finicky in storage, especially at low humidity. The humidity in our home is annoyingly low during winter, and I know exactly what'll happen: I'll forget about the tubers, they'll dry out a little too much, and I'll struggle to bring them back. 

Dahlia tuber all shriveled up and nonviable. Yes, one tuber in my order was like this, believe it or not. Unfortunately, the replacement really wasn't any better. I'll be missing that variety this year, it was the one I was most looking forward to!

    Third, if I need to dig and divide tubers, I will have better luck finding eyes in the spring as they're waking up. This will give me more accurate viable tuber counts. 

    Fourth, the plants themselves seem to be performing a little better having been left in ground. With blooms in May, the in-ground tubers have outperformed the ones that aren't in the ground. Early blooms and happier plants? I won't argue with that! They pair beautifully with my Agave Zinnias, so having dahlias earlier in the season helps with boquets.

    Fifth, I don't have to worry about trying to find a spot in my home to store tubers. Going into winter, I'm already short on space: I have other plants tucked onto counters, squash crammed into all sorts of places (see my tips for growing butternut squash), jars upon jars of dehydrated food lining the pantry, boxes full of old toys and trinkets to declutter, holiday gifts stuffed in the closet, etc. We're really short on space during the fall and early winter, making dahlia tuber storage hard. 

I love the beautiful, sunny blooms of this particular dahlia!

 Dahlias Handled Our Tennessee Winter, Can They Survive Yours? 

    Discussion time!

    Have you tried to overwinter dahlias in your zone? 

    What growing zone and state are you in? 

    Do you typically dig your tubers and store them indoors? What's your storage method?