I just cleared off some upstairs (warmer) light shelves, and the upper one has 12+ inches of head space, so I do have a place to put them... How big a pot would they need? 4"? If they have started sprouting, do they need to be planted or will they "hold" for a few weeks?
My current "method" would make you wince. I got some dollar store plastic baskets, the kind with lots of holes in the sides, and I drilled a few 1" holes in the bottom. I put the dahlia tubers into the baskets with potting mix and time-release fertilizer, then planted the basket so the roots would be below ground level. It does make them easy to find and lift in fall! I've just been letting the baskets go dry and storing them in the garage (cool but not freezing) over the winter. I started with 8 two years ago, and I had 6 last summer... we'll see how they are doing this spring. I might have to step up my game!
