Yes, you can save the tubers.

Thank you Jean - I have gladioli that I plant each year, so is it OK to save the dahlias the same way I save the gladioli? We use a large container and fill it with very dry sand, and then keep it all winter under the house where the temperature is about 36 to 40

Pat

Sounds about right, Peter. I haven't used sand, I use peat moss and another person who has been growing and saving them for about a long as I have been alive uses cedar shavings.

They are brought in, all roots and anything not a tuber is cut off, they air dry for around an hour and are then placed in plastic bags packed in dry material. The plastic bag is to control humidity so they don't dessicate. The plastic bag is then placed into a paper bag or box to keep light out. This is then stored in the coolest spot in the house that is well above freezing.

Thanks user - Do you seal the plastic bag or leave it open?
You would think that too much moisture would make them grow prematurely.

The recommendations I've received through the years is to avoid plastic bags because the tubers can mold. Better to settle them into an open-top box filled with sand, peat moss, or even sawdust.

Peter,

The advice you will recieve will conflict. The reason for the conflict is the need to create a balance in humidity.

We store tubers in dry, moisture absorbing materials like peat, wood shavings, saw dust or whatever to reduce humidity in order to avoid rot, mold, fungi and other humidity related problems. We store tubers in plastic bags to ensure that the tubers retain sufficient humidity that they do not dessicate and die in storage.

What we must achieve for good storage is the right amount of humidity to avoid dessication while avoiding an excess of humidity that leads to rots and other problems.

How do we do this?

Really, I have no answer. I know what I do with good success and I have already told you about that. Others do things differently.

We each have differing conditions and things like relative humidity, temperature, bacteria and fungi spores in the air and a host of other things vary from area to area and person to person so there is no right answer.

Unfortunately you will simply have to experiment on your own to find what works best for you. If you move then what works best may change. If you change your storage area from your basement to your living area things may change. The good news is that most plants are fairly hardy and will tolerate our ignorance of their needs pretty well.

My recomendation for you is chose whatever packing medium you wish and place half your dahlia tubers in it enclosed in plastic bags and the other half in paper or boxes rather than plastic. Come planting time take note of which show the best survival rate and use that method in the future.

I wish there was a more concrete and universal answer, but there isn't - at least not that I am aware of. Plastic bag or not will work OK, but which is best just depends.

I live in Arkansas now, but was raised in Washington state. My mother and stepfather always left their glad's and dahlias in the ground. As far as I know, they never take anything up. They just leave them be over winter. Is this something that varies by zone??

Overwintering glads and dahlias definitely varies by zone and by plant. Neither are capable of surviving sustained hard deep freezes, thus we dig them up to overwinter where they can be cool but not frozen solid. With a thick overcoat of mulch, dahlias are usually safe outside zone 8A and warmer, but glads are more variable with most being okay in zone 7 and a few actually making it through a zone 6 winter (I've heard of some that were okay in zone 5, but I have no personal knowledge, and I suspect that applied only to a few extra-hardy glads). Don't forget that micro-climate can matter -- being in a protected place, south of the house (better yet is *close* to the house) and thickly mulched can keep the soil a zone or so warmer than otherwise.