Your Storage Methods

Here it is: the results of crowd sourcing from the Dahlia Lovers Newsletter. I asked you how you store your tubers and you all really let me know!

I’ve divided this by climate as much as I could: Warm Climate and Cold Climate. Although there were some where I didn’t know the growing climate.

Cold Climate Storage Methods:
Martin P- West Virginia—
I am gardening in West Virginia, on the Ohio river. I process small numbers of tubers and store them lightly covered in vermiculite in side plastic grocery bags. The bags are placed inside cardboard boxes, around 10 bags per box with the tops left open for breathing the moisture. The boxes are stored inside a larger box that had a piece of furniture delivered in it. The smaller boxes are the size of Hello Fresh grocery deliveries. The larger box holds three or four boxes of dahlias. So I am estimating around 40 tubers or small clumps of tubers.

The larger box sits on an old large dog bed, I guess old carpet could also keep the box off the concrete floor of the garage. It is attached to the house so does not quite freeze inside. The lid of the large box is closed but not sealed. When it gets to below 15F I cover the box with a couple of blankets.

So far this has worked for 5 years. I check the state of the tubers one or twice to make sure they are not too dry.

This method has worked for 5 years so far.

I do also leave a few in the ground, provided it is well drained they have usually come back. The clumps get very large though and performance reduces as a result. This year I reduced a couple of clumps and replanted, let’s see if that is successful.

As a side note I have taken to drying a few dahlias this year. Black Jack looks stunning dried turning even darker!

Christa- Bridlewood Blooms, NY—
We do lift the tubers with a sub soiler bar on our tractor and then go behind and lift each by hand onto a trailer. Every plant has already been previously labeled in the field with a hand written flagging tape around each stem and that label stays with each clump. We use metal mesh trailers so the clumps are immediately washed on a trailer (actually, we only wash what we can divide in a day so the rest just go into their bins unwashed, protected by dirt until we are ready for the next batch) and then they go into labeled crates on a second trailer. Dividing starts immediately, sanitizing tools between clumps, and the cut tubers are left in 1020 trays to dry for up to 24 hours, depending on their needs. We hand label each tuber with an indelible marker with a name acronym and a number, pack them in vermiculite in shallow clear plastic bins (varying sizes depending on tuber quantity) and store them in our walk in cooler on rolling racks with multiple shelves so all bins are accessible at anytime. Our Coolers are kept at 40 degrees, and once temps fall below freezing in our area, we use an electric heater on a thermostatically controlled Ink Bird Smart Meter, set to come on at 38 and turn off at 42, and a Govee to send that info to my phone 24/7. For the first couple days I monitor the bins twice a day and crack open the lids on any bins if I see any condensation in their clear walls, but once all the tubers are acclimated, they are closed tight and checked on twice a month.  Humidity is kept between 85-90. The key for me is the consistent cold temperature I can achieve in an insulated space like this. We store over 5500 tubers with amazing success.

A. R. —-
I’m a novice home gardener - no cooler, an unheated garage - and last winter I wrapped a few tubers in plastic wrap and stored in a cardboard box in an unheated room in the basement. I expected all of them to shrivel and instead they all made it! 

(They didn’t all have eyes… but none of them shriveled up. I found one that I didn’t plant in a corner of the yard in July... I thought it had no eyes but it was pushing two tiny shoots, even above ground. I buried it and got a full size plant. Dahlias are awesome.)

I’m doing the same thing again. Expecting 100% success seems unreasonable, but who knows?

Lisa, Massachusetts—
I grow dahlias in zone 6 (Massachusetts). I lift them on a dry day, shake off most of the soil, drop them into brown paper grocery bags, and write the cultivar on the bag with a Sharpie. Then I close the bags loosely (crease the tops and fold over) and put them in my basement until spring. I usually lose a few tubers to drying out, but the ones that can handle it keep multiplying.  It's survival of the fittest. 

Amy W- New England—
I live in New England so have to dig ‘em up every fall. We wash them, dry them well, then take them to the basement where they are placed in wood shavings in crates. Our basement runs between 50 and 60 degrees all winter. We’ll divide them in the spring unless we get ambitious (doubtful) over the winter. 

Carolyn T- Massachusetts—
I grow about 12 different types of dahlias in my Massachusetts home garden. In September I make sure each dahlia plant is labeled with the color, height, and name of the dahlia. Then in October after a  hard frost I cut the dahlia stalks down to about 5 inches and lift up my dahlia tubers with a pitch fork. I shake off the excess soil and rinse the tubers with a strong stream of water. After they dry for a day, I look for budding eyes and separate the clumps, making sure to label them either with a Sharpie, flagging tape, or a piece of a window blind. I store the tubers in plastic labeled shoe boxes filled with vermiculite. I keep the boxes in my unheated, attached garage where the temperature stays around 40 degrees. It’s warmer in November, but the tubers seem to do well. I check the tubers about every 3 weeks to see if the tubers are drying out or if they are developing any mold. 

Brad S.—
Like others, it seems every year is a struggle finding the right method for storing my dahlia "clumps" so they don't mold or get bacteria melt. God the cleaning off the soil, a place to dry out....
I do it differently now. On a day when the soil isn't wet, I wheelbarrow a bale of peat over to the dahlia garden. I dig up the first clump. Brush off any large dirt clogs is enough - leave the rest of it in place. I only cut the stem. I toss the clump on top of a layer of peat on the bottom of the wheelbarrow. Throw a light layer of peat on the clump. On to the next, and next and...each placed closely with its neighbor, even overlapping each other's tubers. Then add a thicker layer of peat to covers those clumps. Next I lay in another group of clumps. Repeat the covering, and so on. When near the top of the wheelbarrow I cover everything with a thick layer of peat. I want the top to look like a wheelbarrow of peat. I will have 60 to 80 clumps of varying sizes and usually can fit them all in my very large double wheel wheelbarrow - depending on how large they are. This quick and easy wheelbarrow is put into my garage for the winter. The peat draws excess moisture evenly supplying the whole group. Check each month. Look a little dry? I pour about a qt of water or less on the surface with a sprinkler watering can. My garage temp can be 50⁰ to 30⁰.

Spring arrives. My dahlias look exactly like they did when packed away, only fresher because they are getting as psyched about spring as I am. How convenient! Just wheel them back to the dahlia garden with last year's holes ready to receive my dahlias. Maybe I will by lots of new tubers...and another wheelbarrow.

Warm Climate Storage Methods:
Djana V—
So my storage method is just cutting down my dahlias and covering with lots of pine needles and then laying a black trash bag over the pine needles and then covering with more pine needles. I grow everything in a plastic 12inch pots from Lowes also in a warmer area so I don't have to worry about frost. 

Ellie- Zone 8, SC—
I am very fortunate to live in zone 8 and do not have to store my dahlias.  I will mulch well and divide in spring.

Shirley, Zone 8, SC—
Here’s my dahlia storage plan courtesy of Helene: The bed where my dahlias are planted had a large oak in it. Helene took out the tree with the surrounding root bed attached with all the bulbs, tubers and other plants in it. I was only able to find one tuber out of 6, several spider lily bulbs and some iris rhizomes afterwards. The remaining 5 dahlias are still in the ground - somewhere. It’ll be interesting to see if they come back up next spring and where they’re now located. All the plant markers were blown away so those that do sprout will be a mystery until they bloom.

Audra V—
I cover my beds with very thick layer of fallen leaves. :) I didn’t even know I should have been pulling the bulbs until this year.

Janet L. Upstate SC—
I typically dig my dahlia tubers up, rinse them off, layer them in a bin with peat moss and store in our basement. In spring, I divide and plant. 

This year, however, I left the dahlias in and mulched with grass and leaves that I bagged with my riding mower. The reason being that this fall I needed to divide my lotus tubers, which I normally do in spring; they took the peat moss.

Hoping both species fare well. To be determined.

Cindy B- TN—
I am in Knoxville, TN zone 7b. I dig and divide in the Fall. I wrap my tubers in plastic wrap and store them in my crawlspace in lidded plastic storage bins.  I monitor temp & humidity with a Govee device. 

Courtney, Beija-Flor Blooms, São Pedro de Alcântara, SC, Brasil—
Here in Brazil, we leave them in the ground. We have cold-ish weather but not hard freezes, and we lack the nifty resources you have to store tubers—and the things we do have, like bins, are ridiculously expensive.  But leaving them in the ground risks rot from the water that doesn’t drain well from our clay soils. 

Thanks for all the info you publish. Dahlias aren’t widely grown in Brazil, and resources for growing here are almost nonexistent. It’s actually so rare that varieties are referred to by color, as in “the red dahlia”, because there’s only one red dahlia available to buy (and rarely at that).  Anyway, you have saved me many tears as I try to master this and in turn help others. 

Happy digging and dividing!

Randi P- CA—
I only grow dahlias in large pots since my gardening space is small and I like to use it mostly for food crops ( although this season I grew one in the ground where I will leave it to overwinter with a few inches of mulch on top). Once the tops have died, I move all the pots into the unheated hoop house where the soil eventually dries by sometime in March? Once I see growth emerging, I pull out the tubers, divide and re-pot. This method has worked really well for many years. 

Unfortunately, it was extremely hot here this summer and many died, (in gallon and larger pots), even those under shade cloth. I will either need to get them in the ground this spring or figure out how to shade the pots themselves (as I believe that the soil got too hot).