How to properly store Dahlia tubers for Winter?

[journey11]

I finally got my first frost up here a couple days ago and a light freeze last night. That did in the last of my flowers that were determined to keep blooming.

So I dug up my dahlias today. I was surprised how difficult it was to dig up the taller ones! I also didn't expect the tubers to be so crisp and juicy. I broke off a few and cut into a couple. Are those toast?

I was wondering what the proper way to prepare and store them is? Do I let them dry for a bit first? Cut the tops all the way of or leave some? Do they need dividing, now or ever? Do you pack them in sawdust or put them in an onion bag? At what temps/humidity or ideal place do I keep them?

I really enjoyed these babies and hope they'll make it for next year! :rainbow-sun

 

[lesa]

I just dug mine today, as well. I let them dry out (my soil was quite wet). Then I will put them in a box with peat moss. Come spring, I divide them up, into smaller clumps and plant in pots. Then after danger of frost, I transfer to ground. Steve, will chime in and tell us how you are really supposed to do it. He is the expert!

 

[journey11]

Yeah, I would have PM'd Steve, but I didn't want to put him on the spot!

I'm glad to hear that they can be divided too. Yea!

 

[digitS']

No expert here, all I can do is tell you what I do.

Now keep in mind that when I had just a few and little experience (and a better back) my technique was real simple. I would cut the plants just above the soil, lift the entire clump with a spading fork (or, 2), and plunk the thing down in a box of leaves. The whole thing was carried to the basement where it could stay in the cool darkness for 6 months.

Anything that didn't look like it would grow was removed in the spring but I don't want to carry all that extra stuff up and down the stairs, anymore!

It seems to help if the plant can go thru a few light frosts and really die back to near the soil surface. Sometimes, it isn't worth the risk to wait when there's a possibility of the roots themselves freezing. That would be bad news, indeed.

So, I cut the plant down where it is easy to handle and pop it out of the ground with a spading fork. The roots are sprayed with the hose to remove the soil and rocks.

The stalks are completely removed and last year's tuber is cut off and discarded. It is easy to recognize that part, it looks quite a bit rougher and darker than the other tubers. Any damaged tubers should probably be removed. The eyes for next year's plants are in the neck of the tuber. If there are any breaks or cuts below that area, rot may kill the tuber before it has any chance to grow.

I have used peat moss to store the roots for the last 15 years. Some people don't like peat and use vermiculite, instead. I imagine that works fine.

The purveyors of bales of peat moss aren't trustworthy as to moisture content of their product. You definitely don't want the peat saturated with water. Often, it has been necessary to break the bale open and scatter the contents out in the open on a tarp to allow it to dry a couple of days.

The tubers themselves, shouldn't be left laying around for more than a couple of days, at most. I put them on the wood floor of my shop until the water has dried off them - usually about 24 hours. Then they go in supermarket bags with the peat moss.

A heavy layer of peat moss on the bottom of the bag, then a clump of roots or 2 clumps, then more peat, and it is down to the basement they go.

The top of the bag is left open to the basement air and the bags cover the floor in one room down there. This is not a concrete floor in that room, as in the other rooms of the basement. It's way below the top soil so it is essentially gravel. This is a 100 year old house and that room has shelves for food storage. It works fairly well for potatoes and onions and gladiolas but the spuds and glads have begun to grow by March. The dahlias make it thru until May in pretty good shape.

In another home, I would store the dahlias on the basement floor, under the bottom shelf as far as possible from any heat down there. That worked well, also. The ideal temperature is sometimes said to be 40F. I suppose that's true but it would only be during the coldest weeks that the temperature, even in that room, is that low.

A fairly moist environment is probably best even if wet peat moss should be avoided because of disease.

I wait until spring to do any dividing of the clumps unless the tubers have been accidentally broken loose. The tiny tubers are likely to be dehydrated by spring. I can't really trust any that are smaller than about 1" in diameter to make it thru until spring. Still, there should be several from each healthy plant that are larger than 1".

Best I can suggest . . . some folks dust their tubers with sulfur; others use captan or another fungicide. I never have.

Steve.

 

[journey11]

Thanks guys. I'm afraid I screwed up a couple of the big ones. I had a hard time getting them out and cut/broke a couple. I had a spading fork--wish I had thought to use that instead of the shovel! They were really different than I expected.

Hmm... I'm probably going to have to store them in my sunroom. It's the only space I have that the woodstove doesn't heat. Some nights it can go below freezing, but I'll just have to be more vigilant. I can open the door into the house when it does that. I froze a couple of my epiphyllums last winter, actually about half of them! It haunts me still....

 

[hoodat]

One thing to keep in mind is that mice and squirrels find them a tasty treat to nibble on all Winter if you don't keep them away from them.

 

[journey11]

I'll bet so. I was really surprised how much they resemble a sweet potato!

 

[lesa]

It seems to work well to divide them in the spring. By then, you will see which tubers are viable and which have kind of shriveled up. Sometimes those cut ones will heal over. I am not sure if they survive or not- but they don't always look dead...I planted some of mine in really good soil last year and they died. The group I planted in an old unamended garden, grew better than I've ever had them!! I might use some of mine in pots next year- the flowers are so pretty. The long wait for spring begins!!

 

[digitS']

I came across this bit of information. The idea of dahlia tubers as food has intrigued me but I use insecticides on them , mostly to try to limit the damage spider mites cause in this arid climate.

"The roots are so significant that Andreas Dahl tried to popularize them as an alternative to potatoes for food. They were used to an extent in France and along the Mediterranean coast, but their peculiar flavor limited their adoption."

So, if you haven't sprayed the plants with a systemic bug-killer -- now is your chance to find out what they taste like. You could use the damaged tubers or the ones about the size of your thumb. They are not as likely to make it thru the months of storage anyway.

Steve

 

[lesa]

Hmm, I think I'll have to be a little hungrier than I am, right now!! They look kinda gross!