Dahlia experiments

Dahlia 'Teesbrooke Redeye'Whoever says that gardening is a completely stress-free (a)vocation must never plant anything let alone those plants that come with their own set of instructions. Like dahlias. For starters, dahlias are generally sold as tubers that resemble nothing more inspiring than a dead mouse. You have to take it on faith and cross your fingers that if you put that bit of brown pith in the ground (at a very certain depth and heaven forbid you water it in) that it will grow into a plant with, in some cases, dinner-plate sized flowers. Dahlia growth itself inspires panic particularly if you’re like me and have ever forgotten to stake them before a windstorm. And then there’s the anxiety of overwintering them. I’m still debating how to store the tubers this winter and am preemptively worried that they won’t survive.

The Rules for dahlia winter storage are as follows: Allow them to be hit by a frost and then leave them in the ground for a few days before digging them, drying them, cleaning them, dusting them/dipping them in fungicide, packing them in vermiculite/peat moss/sawdust and placing them in a dark vault with consistent humidity and a constant temperature in the neighborhood of 40 degrees Fahrenheit. We play fast and loose with those rules and I have to say that aside from one sad year when most of our tubers rotted moments before we planted them in June, we’ve had a pretty decent survival rate (knock wood).Dahlia 'Willie Willie'

We can’t always wait for a frost and even when we do, we can’t always wait those few days before digging them up. Why do we have to wait? The only reason I could find for that rule is that the frost triggers the tuber to build a thicker skin more resistant to moisture loss. That does make a certain sense if it’s true but like I said, we’ve had success with digging up pre-frost too. We also never use fungicide and usually keep them in boxes or paper bags (in sawdust and out) in the damp, furnace-warm cellar.

It seems to me, based on our experience, that some dahlias are simply sturdier and more likely to survive winter storage than others. I can almost tell as I dig them which ones we’ll have to reorder. Some plants make a hearty bundle of baby-fat tubers while others make you wonder how a giant plant survived and even thrived on such tiny feet. In the end (the fall), it all comes down to another winter’s experiment. We’ve had to dig the dahlias out of the North Garden to make way for tulips and we’ll leave others in as long as possible and maybe we’ll see if the timing makes a difference in survival rates.

Our other dahlia experiment this year was buying cuttings from Corralitos Gardens. Gail and I give them big green thumbs-up. It’s hard to believe that something so tiny and fragile could grow in one short season into a full-sized plant with hundreds of blossoms from an early start to finish along with a full set of tubers for me to stress over now. Every plant we ordered was as perfect and true as the catalog picture and every one knocked our socks off.

The dahlia cuttings as they arrivedDahlia 'Granville' (left) just planted in May and already bloomingDahlia 'Granville' in the lower left corner - late AugustLong-lived Dahlia 'Sympathy' (left) and new-to-us by cuttings 'Micro Knockout'

I’d like to think that dahlias aren’t as tricky as they’re made out to be. Do you grow dahlias and save them from year to year? Do you follow The Rules? Have you ever bought them as cuttings?

2 thoughts on “Dahlia experiments

  1. I do have a few dahlias and the rules? Hmmm… throw ‘em in some damp peat moss and store them in the furnace room of the barn. They have two chances, they can live or they can die. I find if I have no expectations of their survival, I am always rewarded with a few good tubers. LOL

    Layanee, I think that’s just the right attitude to adopt when it comes to overwintering dahlias! -kris

  2. My Dad used to grow a LOT of dahlias at one time, and I remember them being spread on newspapers to dry in the cellar (they were dug up each fall) then stored in a basket full of sawdust for the winter. I don’t believe he ever did anything more than plant them with a healthy hand full of composted horse manure from the neighbour’s barn. :)

    Nancy, He must have had such a beautiful display! -kris

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