Many people have different methods, ranging from the very elaborate to very simple. I dug mine up yesterday as the frost had made"cooked spinach" out of the plants (sad to see). I cut down the foliage, dug up the tubers carefully with a garden fork, shook off the excess soil and placed them on newspapers (I never wash them completely - I don't find it necessary). Now they are all in the basement, where they will dry off for a week or two. But don't wait too long or they will start to shrivel. Last year, circumstances didn't allow me to tend to them all right away, so I simply sprayed them lightly with water, and that kept them plump and firm. The rest is basic: I trim the roots and any remaining stems, wrap each tuber in newspaper or rag paper, and store them together in a box or crate (I also use an old chest of drawers, very handy as I can check on them now and again throughout the winter to make sure they are ok. Most of my tubers survived that way and I have had a higher survival rate than storing in vermiculite. I hope that helps a bit.

Thanks so much. I've never overwintered dahlias, just bought new in the spring. This year I got some "Dinner Plate" dahlias which bloomed spectacularly and I'd like to have them again. I think I'll put them in an inner corner of my garage. My garage is attached to the house but not insulated, but I think the wall that's attached to the house never gets to freezing. Do you wait until the foliage is at the "cooked spinach" stage? We haven't had a frost yet. Thanks for the tips.

Well, some folks wait - some, like me, cannot bear to cut down the plant while buds are still showing promise of opening. Benefits of digging up the tubers earlier is the benefit of mild weather. One year I was digging with snow in the air - that wasn't much fun. Apparently you can wait up to two weeks after freezing to dig them up, but I never want to take the risk.

Do you close the top of the box? I have lined the box with newspaper and will be putting the tubers in plastic grocery bags after cleaning them off and putting powder on them. Than into the cellar or the attic.

My problem is that I only have an unheated greenhouse. Will they be able to withstand our pacific northwest winter wrapped up in newspaper/in a bin, but not in some kind of insulated space, ie a basement or attic ? My object is to not have to fuss with them over the winter.

If it freezes in your unheated greenhouse-- & it will-- then they'll freeze & be mush. The ideal temp to store dahlia tubers is above freezing & below 45 degrees F. Here in the PNW we don't get a lot of severe temps very often but it only takes a few days of freezing temperatures to ruin your tubers. If you could put a heater in there that comes on at somewhere around 35-37 degrees or so you'd do OK.

I am getting ready to dig up my first dahlias and they will be stored in the basement. Should I worry about mice? We don't have a lot but since we live close to an open field, we often get one or two during the winter months.

Thanks.
Marianne

Yes- the mice will gnaw on them-- so set traps & catch them before they get to the tubers. (Voice of experience!)

Could they be stored wrapped in newspaper in a cooler outside or do they need to breath. I,m thinking a cooler is air tight.

I dig mine and wash them and then let them dry in the house for a few days and then layer them with vermiculite or dry peat moss in a big styrofoam box with a lid and then put them in an old chest type freezer in our unheated barn.Have kept them upstairs or on the unheated front porch but the light makes them sprout too early in the spring.Dark and dry is good and not freezing.I also store my cannas like this in sawdust and some lilies that are not hardy.Posy Pet

Want to know more about Over Wintering Dahlias? A lot more? The article below points to some of the best internet sources for information on digging, dividing and storing dahlias.

Here is a link that might be useful: OVER WINTERING DAHLIAS

Excellent link upwithdahlias. Pretty much covers all the bases known to date.